diff --git a/apps/backend/src/services/session/session-wx.js b/apps/backend/src/services/session/session-wx.ts
similarity index 78%
rename from apps/backend/src/services/session/session-wx.js
rename to apps/backend/src/services/session/session-wx.ts
index 09a38583..e66fcab7 100644
--- a/apps/backend/src/services/session/session-wx.js
+++ b/apps/backend/src/services/session/session-wx.ts
@@ -1,12 +1,64 @@
-// @ts-nocheck
+/// <reference lib="dom" />
 
 import fs from 'node:fs/promises'
 
 import { downloadRemoteQrImage, logBrowserSessionDebug, waitForFrame } from './session-login-shared.js'
 
-export async function ensureWxLoginReady(page) {
+type LocatorLike = {
+  first: () => LocatorLike
+  waitFor: (options?: { state?: string; timeout?: number }) => Promise<void>
+  screenshot: (options: { path: string }) => Promise<void>
+  isVisible: () => Promise<boolean>
+  click: (options?: { timeout?: number }) => Promise<void>
+  evaluate: <T = unknown>(callback: (element: Element) => T | Promise<T>) => Promise<T>
+}
+
+type FrameLike = {
+  url: () => string
+  locator: (selector: string) => LocatorLike
+  waitForTimeout: (milliseconds: number) => Promise<void>
+  evaluate: <T = any>(callback: any) => Promise<T>
+}
+
+type PageLike = {
+  frames: () => FrameLike[]
+  waitForTimeout: (milliseconds: number) => Promise<void>
+  context: () => {
+    request: {
+      get: (url: string, options?: any) => Promise<{
+        ok: () => boolean
+        status: () => number
+        body: () => Promise<Buffer>
+      }>
+    }
+  }
+}
+
+type WxLoginViewState = {
+  qrVisible: boolean
+  quickLoginVisible: boolean
+  switchToNormalVisible: boolean
+  qrCandidates: Array<{
+    index: number
+    visible: boolean
+    src: string
+    naturalWidth: number
+  }>
+  bodyText: string
+}
+
+type WxQrState = {
+  visible: boolean
+  qrVisible?: boolean
+  scanned: boolean
+  expired: boolean
+  message: string
+  frameUrl?: string
+}
+
+export async function ensureWxLoginReady(page: PageLike): Promise<void> {
   try {
-    const frame = await waitForFrame(
+    const frame = await waitForFrame<FrameLike>(
       page,
       (item) => item.url().includes('open.weixin.qq.com/connect/qrconnect'),
       10_000,
@@ -52,9 +104,9 @@ export async function ensureWxLoginReady(page) {
   }
 }
 
-export async function captureWxQrImage(page, qrImagePath) {
+export async function captureWxQrImage(page: PageLike, qrImagePath: string): Promise<void> {
   const qrLocator = await findWxQrLocator(page)
-  const frame = await waitForFrame(
+  const frame = await waitForFrame<FrameLike>(
     page,
     (item) => item.url().includes('open.weixin.qq.com/connect/qrconnect'),
     10_000,
@@ -70,11 +122,11 @@ export async function captureWxQrImage(page, qrImagePath) {
     const downloaded = await downloadRemoteQrImage(page, qrUrl, qrImagePath, frame.url(), 'wx')
     logBrowserSessionDebug('wx.capture.downloadResult', {
       qrUrl,
-      downloaded: Boolean(downloaded?.length),
+      downloaded: Buffer.isBuffer(downloaded) && downloaded.length > 0,
       qrImagePath,
     })
 
-    if (downloaded?.length) {
+    if (Buffer.isBuffer(downloaded) && downloaded.length > 0) {
       await fs.writeFile(qrImagePath, downloaded)
       return
     }
@@ -86,10 +138,10 @@ export async function captureWxQrImage(page, qrImagePath) {
   await qrLocator.screenshot({ path: qrImagePath })
 }
 
-export async function findWxQrLocator(page) {
+export async function findWxQrLocator(page: PageLike): Promise<LocatorLike> {
   await ensureWxLoginReady(page)
 
-  const frame = await waitForFrame(
+  const frame = await waitForFrame<FrameLike>(
     page,
     (item) => item.url().includes('open.weixin.qq.com/connect/qrconnect'),
   )
@@ -109,7 +161,7 @@ export async function findWxQrLocator(page) {
   return locator
 }
 
-export async function extractWxQrState(page) {
+export async function extractWxQrState(page: Pick<PageLike, 'frames'>): Promise<WxQrState> {
   const frame = page.frames().find((item) => item.url().includes('open.weixin.qq.com/connect/qrconnect'))
 
   if (!frame) {
@@ -146,10 +198,10 @@ export async function extractWxQrState(page) {
   }
 }
 
-async function inspectWxLoginView(frame) {
+async function inspectWxLoginView(frame: FrameLike): Promise<WxLoginViewState> {
   return frame
     .evaluate(() => {
-      const isVisible = (element) => {
+      const isVisible = (element: Element | null) => {
         if (!(element instanceof HTMLElement)) {
           return false
         }
@@ -203,7 +255,7 @@ async function inspectWxLoginView(frame) {
     }))
 }
 
-async function switchWxQuickLoginToQr(frame) {
+async function switchWxQuickLoginToQr(frame: FrameLike): Promise<boolean> {
   const switcherCandidates = [
     frame.locator('.js_switchToNormal:visible').first(),
     frame.locator('.js_switchToNormal').first(),
@@ -279,10 +331,10 @@ async function switchWxQuickLoginToQr(frame) {
     .catch(() => false)
 }
 
-async function resolveWxQrImageUrl(frame) {
+async function resolveWxQrImageUrl(frame: FrameLike): Promise<string> {
   return frame
     .evaluate(() => {
-      const isVisible = (element) => {
+      const isVisible = (element: Element | null) => {
         if (!(element instanceof HTMLElement)) {
           return false
         }
diff --git a/docs/backend-typescript-migration-plan.md b/docs/backend-typescript-migration-plan.md
index 1e7f0401..0caa7fe7 100644
--- a/docs/backend-typescript-migration-plan.md
+++ b/docs/backend-typescript-migration-plan.md
@@ -480,6 +480,14 @@
     - `npm run typecheck`
     - `npm run build`
     - `npm test` 共 139 个用例通过
+101. 腾讯浏览器 WX 登录模块迁移到 `.ts`：
+    - `src/services/session/session-wx.ts`
+102. WX 登录 iframe、快捷登录切换、二维码候选状态、远程下载 fallback、二维码 locator 与扫码状态已显式类型化
+103. Docker 内验证通过：
+    - `src/services/session/session.test.js` 共 14 个用例通过
+    - `npm run typecheck`
+    - `npm run build`
+    - `npm test` 共 139 个用例通过
 
 ## 下一步建议