diff --git a/docs/douyin-pay-integration.md b/docs/douyin-pay-integration.md
index 7283b6e..a5090a7 100644
--- a/docs/douyin-pay-integration.md
+++ b/docs/douyin-pay-integration.md
@@ -128,6 +128,19 @@ HBuilderX 5.24 App 资源编译及导出成功，仅有既有 CSS Autoprefixer 
 本次只改 JavaScript、测试和文档，不改后端、原生插件、SQL、接口或页面样式。尚未真机实付。
 HBuilderX 5.24 App 资源编译与导出成功，只有既有 CSS Autoprefixer 注释警告。
 
+## 当前订单与缓存旧单隔离（2026-09-10）
+
+本节覆盖前文“点击支付先恢复账号缓存旧单”的说明。原逻辑会在取消 200 元订单后，购买其他 0.2 元商品时再次唤起 200 元旧单，必须移除。
+
+- 与微信/支付宝一致，`prepareDouyinPay` 仅检查 App、登录、客户端可用性及正在进行的调用，不从账号缓存中选订单，不续付、不关单、不跳旧单结果页。
+- 商品结算、充值、订单详情仍分别调用现有业务接口，以本次接口返回的数据调用 `appDypayFun`，旧单不再拦截当前下单。
+- 只有当前响应 `payment.orderNum` 与缓存订单号完全一致时才查单续付；缓存属于另一单时，验证当前签名参数，释放残留客户端回调，再调用当前订单的 SDK 参数。金额和签名不在客户端改写。
+- 成功/失败继续使用微信/支付宝的现有结果页，不新增弹窗。实际尚在运行的 SDK 调用仍防重复点击；迟到的旧回调不得处理新订单。
+- 缓存只用于最近一次支付的 App 恢复，不是用户待支付订单清单。新支付发起后恢复记录指向新订单；旧订单仍保留在服务端，由回调、定时查单、订单详情处理，不自动关单或标记失败。若新参数无效/初始化失败，旧恢复记录不覆盖。
+
+验证：`node --test tests/douyin-integration.test.cjs tests/douyin-uts.test.cjs`（需设置下节所述 HBUILDERX_HOME）51 项通过。新增测试经过真实前端 API 包装函数验证商品结算、充值和订单补付的当前响应，SDK/服务端均使用模拟数据，不产生真实交易。HBuilderX 5.24 App 资源编译、导出通过，仅有既有 CSS 注释警告。
+本次仅修改 `utils/douyin-pay.js`、回归测试和文档，无后端、SQL、接口、原生插件变更。仍需真机验收“200 元取消 → 0.2 元支付”的收银台金额与订单归属；不能把模拟测试当作实付验证。
+
 ## 双端 UTS 编译兼容（2026-09-10，插件 0.2.1）
 
 基于用户确认的远端 `dev_codex` / `3e2e182`，不改变支付页面或后端逻辑。
diff --git a/tests/douyin-integration.test.cjs b/tests/douyin-integration.test.cjs
index 585a170..0a7504b 100644
--- a/tests/douyin-integration.test.cjs
+++ b/tests/douyin-integration.test.cjs
@@ -19,7 +19,7 @@ function preprocess(source, app) {
 }
 function loadModule(file, context, app = true) {
   const source = preprocess(fs.readFileSync(path.join(root, file), 'utf8'), app)
-    .replace(/^import .*;\r?$/gm, '')
+    .replace(/^import [^\r\n]*;[^\S\r\n]*(?:\/\/[^\r\n]*)?\r?$/gm, '')
     .replace(/export (async function|function)/g, '$1')
     .replace(/export const /g, 'const ')
     .replace(/export default request;/g, '');
@@ -167,7 +167,7 @@ test('request terminates on HTTP500, business500, bad JSON, auth failure and off
   }
 });
 
-test('killed App resumes the original unpaid transaction, without creating another order', async () => {
+test('killed App only resumes the original transaction when the current response selects that same order', async () => {
   const ctx = await payContext();
   // This is exactly the legacy persisted format: only an order number survives process death.
   ctx.uni.storage.set('tb-douyin:test-api:7', payment.orderNum);
@@ -182,8 +182,10 @@ test('killed App resumes the original unpaid transaction, without creating anoth
   };
   ctx.openDypay = (options, cb) => { opened++; assert.equal(options.payInfo.prepayid, 'prepay'); cb({resultCode:'0'}); };
   ctx.queryUntilSettled = async () => ({state:'paid'});
-  // Returning false intentionally stops the caller from creating a NEW order after resuming.
-  assert.equal(await ctx.prepareDouyinPay('douyin'), false);
+  assert.equal(await ctx.prepareDouyinPay('douyin'), true);
+  assert.equal(opened, 0);
+  assert.deepEqual(urls, []);
+  await ctx.appDypayFun(payment);
   assert.equal(opened, 1);
   assert.deepEqual(urls, ['/payment/douyin/resume']);
   assert.equal(ctx.uni.storage.has('tb-douyin:test-api:7'), false);
@@ -199,7 +201,7 @@ test('cold start never opens the SDK or asks for payment and preserves pending s
   assert.deepEqual(ctx.uni.navigations, [failurePage]);
 });
 
-test('unknown, processing, network error and missing backend remain locked', async () => {
+test('retry of the SAME order remains blocked on unknown, processing, network error or missing backend', async () => {
   for (const mode of ['pending','NEW_STATE','offline','missing']) {
     const ctx = await payContext({openDypay:()=>assert.fail('Unknown result must not open SDK'),
       request: async()=> {
@@ -208,7 +210,8 @@ test('unknown, processing, network error and missing backend remain locked', asy
         return {bizcode:100,data:{state:mode,orderNum:payment.orderNum}};
       }});
     ctx.uni.storage.set('tb-douyin:test-api:7', payment.orderNum);
-    assert.equal(await ctx.prepareDouyinPay('douyin'), false);
+    assert.equal(await ctx.prepareDouyinPay('douyin'), true);
+    await ctx.appDypayFun(payment);
     assert.equal(ctx.uni.storage.get('tb-douyin:test-api:7'), payment.orderNum);
   }
 });
@@ -220,38 +223,41 @@ test('terminal server result clears saved order without payment and allows the n
         ? ({bizcode:100,data:{state,orderNum:payment.orderNum}})
         : ({bizcode:100,data:{state:2}})});
     ctx.uni.storage.set('tb-douyin:test-api:7', payment.orderNum);
-    assert.equal(await ctx.prepareDouyinPay('douyin'), false);
+    assert.equal(await ctx.prepareDouyinPay('douyin'), true);
+    await ctx.appDypayFun(payment);
     assert.deepEqual(ctx.uni.navigations, [state === 'paid' ? successPage : failurePage]);
     assert.equal(ctx.uni.storage.has('tb-douyin:test-api:7'), false);
     assert.equal(await ctx.prepareDouyinPay('douyin'), true);
   }
 });
 
-test('closed old transaction unlocks a fresh server order, never reopens old parameters', async () => {
+test('a different current order does not resume or close the cached old transaction', async () => {
   let resets=0, opened;
-  const ctx=await payContext({resetDypay:()=>resets++, request:async options => options.url === '/payment/douyin/resume'
-    ? {bizcode:100,data:{state:'closed',orderNum:'expired-order'}} : {bizcode:100,data:{state:2}},
+  const ctx=await payContext({resetDypay:()=>resets++, request:async options => {
+    assert.equal(options.url, '/payment/queryResult');
+    assert.equal(options.data.orderNum, 'fresh-order');
+    return {bizcode:100,data:{state:2}};
+  },
     openDypay:(options,cb)=>{opened=options.payInfo.prepayid; cb({resultCode:'0'});}});
   ctx.uni.storage.set('tb-douyin:test-api:7','expired-order');
-  assert.equal(await ctx.prepareDouyinPay('douyin'),false);
-  assert.deepEqual(ctx.uni.navigations,[failurePage]);
-  // A NEW user action may now create a fresh order; the closed attempt cannot do it implicitly.
   assert.equal(await ctx.prepareDouyinPay('douyin'),true);
-  assert.equal(resets,1);
+  assert.deepEqual(ctx.uni.navigations,[]);
+  assert.equal(resets,0);
   const fresh={...payment,orderNum:'fresh-order',douyin:{...payment.douyin,prepayId:'fresh-prepay'}};
   await ctx.appDypayFun(fresh);
+  assert.equal(resets,1);
   assert.equal(opened,'fresh-prepay');
   assert.equal(ctx.uni.storage.has('tb-douyin:test-api:7'),false);
 });
 
-test('switching accounts during old-order closure cannot create a new payment', async () => {
+test('switching accounts during same-order reconciliation cannot create a new payment', async () => {
   const ctx=await payContext();
   ctx.request=async()=>{
     ctx.uni.storage.set('user',{userId:8});
     return {bizcode:100,data:{state:'closed',orderNum:'expired-order'}};
   };
   ctx.uni.storage.set('tb-douyin:test-api:7','expired-order');
-  assert.equal(await ctx.prepareDouyinPay('douyin'),false);
+  await ctx.appDypayFun({...payment,orderNum:'expired-order'});
   assert.equal(ctx.uni.storage.get('tb-douyin:test-api:7'),'expired-order');
   assert.deepEqual(ctx.uni.navigations, []);
 });
@@ -260,7 +266,7 @@ test('unconfirmed server state never resets the native lock and explains why', a
   const ctx=await payContext({resetDypay:()=>assert.fail('Unconfirmed native reset'),
     request:async()=>({bizcode:100,data:{state:'pending',reason:'QUERY_FAILED',orderNum:payment.orderNum}})});
   ctx.uni.storage.set('tb-douyin:test-api:7',payment.orderNum);
-  assert.equal(await ctx.prepareDouyinPay('douyin'),false);
+  await ctx.appDypayFun(payment);
   assert.match(ctx.uni.messages.at(-1),/查单失败/);
   assert.equal(ctx.uni.storage.get('tb-douyin:test-api:7'),payment.orderNum);
 });
@@ -271,7 +277,7 @@ test('unpaid server confirmation resets a missing native callback before reiniti
     request:async()=>({bizcode:100,data:{state:'unpaid',orderNum:payment.orderNum,payment}}),
     queryUntilSettled:async()=>({state:'pending'})});
   ctx.uni.storage.set('tb-douyin:test-api:7',payment.orderNum);
-  assert.equal(await ctx.prepareDouyinPay('douyin'),false);
+  await ctx.appDypayFun(payment);
   assert.deepEqual(sequence,['reset','init']);
 });
 
@@ -292,7 +298,7 @@ test('account switch during resume response or native reset cannot invoke SDK',
       return {bizcode:100,data:{state:'unpaid',orderNum:payment.orderNum,payment}};
     };
     if (phase === 'reset') ctx.resetDypay = () => ctx.uni.storage.set('user',{userId:8});
-    await ctx.prepareDouyinPay('douyin');
+    await ctx.appDypayFun(payment);
     assert.equal(ctx.uni.storage.get('tb-douyin:test-api:7'), payment.orderNum);
   }
 });
@@ -304,7 +310,7 @@ test('concurrent clicks and onShow during continuation open only one native paym
     queryUntilSettled: async()=>({state:'paid'}),
     openDypay:(_,cb)=>{ calls++; done = cb; }});
   ctx.uni.storage.set('tb-douyin:test-api:7', payment.orderNum);
-  const first = ctx.prepareDouyinPay('douyin');
+  const first = ctx.appDypayFun(payment);
   await new Promise(resolve=>setImmediate(resolve));
   assert.equal(await ctx.prepareDouyinPay('douyin'), false);
   await ctx.appDypayFun(payment);
@@ -370,7 +376,7 @@ test('full page stack falls back to redirect; navigation failure remains retryab
   assert.equal(failed.uni.storage.get('tb-douyin:test-api:7'),payment.orderNum);
   failed.uni.redirectTo=options=>{ failed.uni.navigations.push(options.url); options.success(); };
   failed.openDypay=()=>assert.fail('Already paid order must not open SDK again');
-  await failed.prepareDouyinPay('douyin');
+  await failed.appDypayFun(payment);
   assert.deepEqual(failed.uni.navigations,[successPage]);
   assert.equal(failed.uni.storage.has('tb-douyin:test-api:7'),false);
 });
@@ -401,7 +407,7 @@ test('resume refuses mismatched order, bad signed parameters and native initiali
     if (mode === 'init') ctx.initDypay = ()=>false;
     ctx.request = async()=>({bizcode:100,data:{state:'unpaid',
       orderNum:mode === 'outer-order' ? 'different' : payment.orderNum,payment:resumePayment}});
-    await ctx.prepareDouyinPay('douyin');
+    await ctx.appDypayFun(payment);
     assert.equal(ctx.uni.storage.get('tb-douyin:test-api:7'), payment.orderNum);
   }
 });
@@ -479,3 +485,117 @@ test('WeChat and Alipay failures retain the same shared failure page', async ()
   ctx.zfbPayFun({type:'app'},2,'ali');
   assert.deepEqual(ctx.uni.navigations,[failurePage,failurePage]);
 });
+
+test('cancel 200 yuan then buy 0.2 yuan uses the current checkout response, never the cached 200 yuan order', async () => {
+  const oldOrder = {...payment, orderNum:'order-200', douyin:{...payment.douyin, prepayId:'prepay-200', sign:'signature-200'}};
+  const current = {...payment, orderNum:'order-0.2', douyin:{...payment.douyin, prepayId:'prepay-0.2', sign:'signature-0.2'}};
+  const opened = [], queried = [], requested = [];
+  let lateOldCallback;
+  const ctx = await payContext({
+    request: async options => {
+      requested.push(options.url);
+      assert.equal(options.url, '/cart/settlementOrder');
+      assert.equal(options.data.goodsId, 'product-0.2');
+      return {bizcode:100, data:current};
+    },
+    queryUntilSettled: async (_, orderNum) => { queried.push(orderNum); return {state:orderNum === 'order-200' ? 'pending' : 'paid'}; },
+    openDypay: (options, cb) => {
+      opened.push(options.payInfo);
+      if (options.payInfo.prepayid === 'prepay-200') { lateOldCallback = cb; cb({resultCode:'1'}); }
+      else cb({resultCode:'0'});
+    }
+  });
+  await ctx.appDypayFun(oldOrder);
+  assert.equal(ctx.uni.storage.get('tb-douyin:test-api:7'), 'order-200');
+  assert.deepEqual(ctx.uni.navigations, [failurePage]);
+  // Same sequence as checkout: preflight -> current business API -> SDK.
+  assert.equal(await ctx.prepareDouyinPay('douyin'), true);
+  assert.equal(opened.length, 1);
+  loadModule('api/cart.js', ctx);
+  const response = await ctx.settlementOrder({goodsId:'product-0.2',payway:'douyin'});
+  await ctx.appDypayFun(response.data);
+  lateOldCallback({resultCode:'0'});
+  assert.deepEqual(requested, ['/cart/settlementOrder']);
+  assert.deepEqual(opened.map(v=>v.prepayid), ['prepay-200','prepay-0.2']);
+  assert.equal(opened[1].sign, 'signature-0.2');
+  assert.deepEqual(queried, ['order-200','order-0.2']);
+  assert.deepEqual(ctx.uni.navigations, [failurePage,successPage]);
+});
+
+test('new purchase, recharge and existing-order payment all ignore an unrelated cached order', async () => {
+  for (const [entry, file, method, url] of [
+    ['purchase','api/cart.js','settlementOrder','/cart/settlementOrder'],
+    ['recharge','api/finance.js','recharge','/finance/recharge'],
+    ['existing-order','api/order.js','payment','/order/payment']
+  ]) {
+    const current={...payment,orderNum:entry,douyin:{...payment.douyin,prepayId:entry}};
+    const ctx = await payContext({request:async options=>{
+      assert.equal(options.url,url);
+      assert.equal(options.data.payway,'douyin');
+      return {bizcode:100,data:current};
+    },
+      queryUntilSettled:async(_, orderNum)=>{assert.equal(orderNum, entry);return {state:'pending'};}});
+    ctx.uni.storage.set('tb-douyin:test-api:7', 'old-200');
+    let received;
+    ctx.openDypay = (options, cb)=>{received=options.payInfo;cb({resultCode:'1'});};
+    assert.equal(await ctx.prepareDouyinPay('douyin'), true);
+    assert.deepEqual(ctx.uni.navigations, []);
+    assert.equal(ctx.uni.storage.get('tb-douyin:test-api:7'), 'old-200');
+    loadModule(file,ctx);
+    const response=await ctx[method]({payway:'douyin'});
+    await ctx.appDypayFun(response.data);
+    assert.equal(received.prepayid, entry);
+    assert.equal(ctx.uni.storage.get('tb-douyin:test-api:7'), entry);
+  }
+});
+
+test('legacy entry also pays the supplied order rather than a cached order', async () => {
+  const ctx=await payContext({request:()=>assert.fail('Unrelated resume'), queryUntilSettled:async()=>({state:'paid'})});
+  ctx.uni.storage.set('tb-douyin:test-api:7','old-200');
+  loadModule('utils/payUtils.js',ctx);
+  let opened;
+  ctx.openDypay=(options,cb)=>{opened=options.payInfo.prepayid;cb({resultCode:'0'});};
+  await ctx.douyinPayFun({...payment.douyin,prepayId:'current-0.2'},2,'current-order');
+  assert.equal(opened,'current-0.2');
+});
+
+test('bad current parameters never fall back to an unrelated old order or reset its native session', async () => {
+  const ctx=await payContext({request:()=>assert.fail('Old-order fallback'),
+    resetDypay:()=>assert.fail('Invalid response must not reset native'),openDypay:()=>assert.fail('Invalid payment')});
+  ctx.uni.storage.set('tb-douyin:test-api:7','old-200');
+  assert.equal(await ctx.prepareDouyinPay('douyin'),true);
+  assert.equal((await ctx.appDypayFun({orderNum:'new',douyin:{appId:'app'}})).state,'error');
+  assert.equal(ctx.uni.storage.get('tb-douyin:test-api:7'),'old-200');
+});
+
+test('restart can reconcile the last attempt but a later new checkout cannot reopen it', async () => {
+  const ctx=await payContext({request:()=>assert.fail('Old resume'),queryUntilSettled:async()=>({state:'pending'})});
+  ctx.uni.storage.set('tb-douyin:test-api:7','old-200');
+  await ctx.resumeDouyinPay();
+  assert.equal(await ctx.prepareDouyinPay('douyin'),true);
+  let opened;
+  ctx.openDypay=(options,cb)=>{opened=options.payInfo.prepayid;cb({resultCode:'1'});};
+  await ctx.appDypayFun({...payment,orderNum:'new-0.2',douyin:{...payment.douyin,prepayId:'new-0.2'}});
+  assert.equal(opened,'new-0.2');
+});
+
+test('an actually running SDK payment still blocks a second order until its callback completes', async () => {
+  let callback, calls=0;
+  const ctx=await payContext({openDypay:(_,cb)=>{calls++;callback=cb;},queryUntilSettled:async()=>({state:'pending'})});
+  const first=ctx.appDypayFun(payment);
+  assert.equal(await ctx.prepareDouyinPay('douyin'),false);
+  await ctx.appDypayFun({...payment,orderNum:'different'});
+  assert.equal(calls,1);
+  callback({resultCode:'1'});
+  await first;
+  assert.equal(await ctx.prepareDouyinPay('douyin'),true);
+});
+
+test('native reset for a different order cannot pay after an account switch', async () => {
+  const ctx=await payContext({openDypay:()=>assert.fail('Wrong account'),
+    resetDypay:()=>ctx.uni.storage.set('user',{userId:8})});
+  ctx.uni.storage.set('tb-douyin:test-api:7','old-200');
+  await ctx.appDypayFun(payment);
+  assert.equal(ctx.uni.storage.get('tb-douyin:test-api:7'),'old-200');
+  assert.equal(ctx.uni.storage.has('tb-douyin:test-api:8'),false);
+});
diff --git a/utils/douyin-pay.js b/utils/douyin-pay.js
index b6c4a62..c1eed4c 100644
--- a/utils/douyin-pay.js
+++ b/utils/douyin-pay.js
@@ -79,7 +79,8 @@ async function showState(state, key, orderNum) {
   uni.showToast({ title: state.message || '支付结果待确认，请稍后查看订单', icon: 'none', duration: 2500 });
 }
 
-// Called only by a user payment action, never by onShow. Renew the SAME transaction on the server.
+// Only called when the CURRENT server response names the cached transaction.
+// A payment click for another product must never authorize this old transaction.
 async function continuePendingPayment(key, orderNum) {
   const response = await request({ url: '/payment/douyin/resume', method: 'POST',
     data: { orderNum }, isShowLoading: false, timeout: 60000 });
@@ -148,10 +149,10 @@ async function executePayment(payment, key) {
   // #endif
 }
 
-// Runs on the payment click BEFORE creating an order. Resume a live original transaction directly.
+// Like WeChat/Alipay, let the current checkout/recharge/order-payment request
+// choose the transaction. The account-wide recovery record is NOT that choice.
 export async function prepareDouyinPay(payway) {
   if (payway !== 'douyin') return true;
-  let paymentKey = '';
   try {
     // #ifndef APP-PLUS
     throw new Error('抖音支付仅支持 Android/iOS App');
@@ -159,29 +160,11 @@ export async function prepareDouyinPay(payway) {
     // #ifdef APP-PLUS
     if (active || resuming) throw new Error('正在处理支付，请勿重复点击');
     const key = accountKey();
-    paymentKey = key;
     if (!key) throw new Error('请先登录后再支付');
-    const previous = uni.getStorageSync(key);
-    if (previous) {
-      failureShown.delete(key);
-      resuming = true;
-      try {
-        await continuePendingPayment(key, previous);
-        // A completed/closed attempt has already entered its result page. Do not create
-        // another order behind that page during the same click.
-        return false;
-      }
-      finally { resuming = false; }
-    }
     if (!canOpenDypay()) throw new Error('请先安装或升级抖音客户端');
     return true;
     // #endif
   } catch (error) {
-    const pending = paymentKey && paymentKey === accountKey() && uni.getStorageSync(paymentKey);
-    if (pending) {
-      await showState({ state: 'pending', message: error.message }, paymentKey, pending);
-      return false;
-    }
     uni.showToast({ title: error.message || '暂时无法支付，请稍后重试', icon: 'none' });
     return false;
   }
@@ -200,10 +183,16 @@ export async function appDypayFun(payment) {
   try {
     if (!key || !payment.orderNum) throw new Error('登录身份或支付订单编号缺失');
     const previous = uni.getStorageSync(key);
-    if (previous) {
-      // Even legacy callers must not open a different payment while the saved one is unresolved.
-      return await continuePendingPayment(key, previous);
+    if (previous === payment.orderNum) {
+      // An explicit retry of this same server-selected order still needs reconciliation.
+      failureShown.delete(key);
+      return await continuePendingPayment(key, payment.orderNum);
     }
+    // Validate the CURRENT response before releasing any stale native callback.
+    // This only resets the client bridge, not the previous server order. Its
+    // settlement remains handled by backend callbacks/query jobs/order details.
+    toSdkPayInfo(payment);
+    if (previous) resetDypay();
     return await executePayment(payment, key);
   } catch (error) {
     if (key && key === accountKey()) {