diff --git a/src/data/repositories/auth_repository.ts b/src/data/repositories/auth_repository.ts
index 3e086ce2..171976ce 100644
--- a/src/data/repositories/auth_repository.ts
+++ b/src/data/repositories/auth_repository.ts
@@ -10,6 +10,8 @@ import {
   GuestLoginResponse,
   LoginRequest,
   LoginResponse,
+  LoginStatus,
+  type LoginStatus as LoginStatusT,
   RefreshTokenRequest,
   RefreshTokenResponse,
   RegisterRequest,
@@ -79,7 +81,7 @@ export class AuthRepository implements IAuthRepository {
           }),
         ),
       );
-      await this._saveLoginData(response);
+      await this._saveLoginData(response, LoginStatus.Email);
       return response;
     });
   }
@@ -131,6 +133,7 @@ export class AuthRepository implements IAuthRepository {
         userLastMessageAt: response.user?.lastMessageAt,
       });
       await this.storage.setGuestToken(response.token);
+      await this.storage.setLoginProvider(LoginStatus.Guest);
       await this.storage.setDeviceId(deviceId);
       if (response.userId) {
         await this.userStorage.setUserId(response.userId);
@@ -150,7 +153,7 @@ export class AuthRepository implements IAuthRepository {
     idToken: string;
     guestId?: string;
   }): Promise<Result<LoginResponse>> {
-    return this._socialLogin(() =>
+    return this._socialLogin(LoginStatus.Google, () =>
       this.api.googleLogin(
         GoogleLoginRequest.from(
           withTestAccountFlag({
@@ -168,7 +171,7 @@ export class AuthRepository implements IAuthRepository {
     accessToken: string;
     guestId?: string;
   }): Promise<Result<LoginResponse>> {
-    return this._socialLogin(() =>
+    return this._socialLogin(LoginStatus.Facebook, () =>
       this.api.facebookLogin(
         FacebookLoginRequest.from(
           withTestAccountFlag({
@@ -186,7 +189,7 @@ export class AuthRepository implements IAuthRepository {
     fbId: string;
     avatarUrl?: string;
   }): Promise<Result<LoginResponse>> {
-    return this._socialLogin(() =>
+    return this._socialLogin(LoginStatus.Facebook, () =>
       this.api.facebookIdLogin(
         FbIdLoginRequest.from(
           withTestAccountFlag({
@@ -204,7 +207,7 @@ export class AuthRepository implements IAuthRepository {
    * 尚未实现该端点，故仓库暂不暴露。等 `AuthApi` 补齐后再加。
    */
   async appleLogin(identityToken: string): Promise<Result<LoginResponse>> {
-    return this._socialLogin(() =>
+    return this._socialLogin(LoginStatus.Apple, () =>
       this.api.appleLogin(
         AppleLoginRequest.from(
           withTestAccountFlag({
@@ -263,11 +266,12 @@ export class AuthRepository implements IAuthRepository {
    * `_saveLoginData` 内部全部 best-effort，存储写失败不抛错。
    */
   private async _socialLogin(
+    provider: LoginStatusT,
     call: () => Promise<LoginResponse>,
   ): Promise<Result<LoginResponse>> {
     return Result.wrap(async () => {
       const response = await call();
-      await this._saveLoginData(response);
+      await this._saveLoginData(response, provider);
       return response;
     });
   }
@@ -277,11 +281,18 @@ export class AuthRepository implements IAuthRepository {
    * 全部 best-effort，错误用 `Logger.warn` 记录但不让登录「失败」——
    * 调用方已经从 API 拿到了 LoginResponse，缓存只是离线加速。
    */
-  private async _saveLoginData(data: LoginResponse): Promise<void> {
+  private async _saveLoginData(
+    data: LoginResponse,
+    provider: LoginStatusT,
+  ): Promise<void> {
     const r1 = await this.storage.setLoginToken(data.token);
     if (!r1.success) {
       log.warn("[AuthRepository] setLoginToken failed", r1.error);
     }
+    const providerResult = await this.storage.setLoginProvider(provider);
+    if (!providerResult.success) {
+      log.warn("[AuthRepository] setLoginProvider failed", providerResult.error);
+    }
     if (data.refreshToken) {
       const r2 = await this.storage.setRefreshToken(data.refreshToken);
       if (!r2.success) {
diff --git a/src/data/storage/auth/auth_storage.ts b/src/data/storage/auth/auth_storage.ts
index 5b612dd6..a330dea0 100644
--- a/src/data/storage/auth/auth_storage.ts
+++ b/src/data/storage/auth/auth_storage.ts
@@ -11,9 +11,10 @@
  *   - 浏览器 → `localStorage` driver；SSR → memory driver（unstorage 自动）
  *   - 单例挂在 class 静态字段，规避 HMR 复用污染
  *   - `hasXxx` = `token != null && token.length > 0`，对齐 Dart 端 `isNotEmpty` 语义
- *   - `clearAuthData` 顺序清理：loginToken → guestToken → refreshToken，任一失败立即返回
+ *   - `clearAuthData` 顺序清理：loginToken → loginProvider → guestToken → refreshToken，任一失败立即返回
  */
 
+import { LoginStatus, type LoginStatus as LoginStatusT } from "@/data/dto/auth";
 import { Result, type Result as ResultT, SpAsyncUtil } from "@/utils";
 import { StorageKeys } from "../storage_keys";
 import type { IAuthStorage } from "./iauth_storage";
@@ -48,6 +49,22 @@ export class AuthStorage implements IAuthStorage {
     return SpAsyncUtil.remove(StorageKeys.loginToken);
   }
 
+  // ---- login provider ----
+
+  async getLoginProvider(): Promise<ResultT<LoginStatusT | null>> {
+    const r = await SpAsyncUtil.getString(StorageKeys.loginProvider);
+    if (!r.success) return Result.err(r.error);
+    if (r.data === null || r.data.length === 0) return Result.ok(null);
+    if (isLoginStatus(r.data)) return Result.ok(r.data);
+    return Result.ok(null);
+  }
+  setLoginProvider(provider: LoginStatusT): Promise<ResultT<void>> {
+    return SpAsyncUtil.setString(StorageKeys.loginProvider, provider);
+  }
+  clearLoginProvider(): Promise<ResultT<void>> {
+    return SpAsyncUtil.remove(StorageKeys.loginProvider);
+  }
+
   // ---- guest token ----
 
   getGuestToken(): Promise<ResultT<string | null>> {
@@ -103,10 +120,16 @@ export class AuthStorage implements IAuthStorage {
   async clearAuthData(): Promise<ResultT<void>> {
     const r1 = await this.clearLoginToken();
     if (!r1.success) return r1;
-    const r2 = await this.clearGuestToken();
+    const r2 = await this.clearLoginProvider();
     if (!r2.success) return r2;
-    const r3 = await this.clearRefreshToken();
+    const r3 = await this.clearGuestToken();
     if (!r3.success) return r3;
+    const r4 = await this.clearRefreshToken();
+    if (!r4.success) return r4;
     return this.clearFacebookId();
   }
 }
+
+function isLoginStatus(value: string): value is LoginStatusT {
+  return Object.values(LoginStatus).includes(value as LoginStatusT);
+}
diff --git a/src/data/storage/auth/iauth_storage.ts b/src/data/storage/auth/iauth_storage.ts
index 11cae11d..da95fbc0 100644
--- a/src/data/storage/auth/iauth_storage.ts
+++ b/src/data/storage/auth/iauth_storage.ts
@@ -4,12 +4,13 @@
  * IAuthStorage 接口
  *
  * 对齐 Dart 端 `IAuthStorage`（lib/data/services/storage/iauth_storage.dart）：
- *   - loginToken / guestToken / deviceId / refreshToken / facebookId 五个字段的 CRUD
+ *   - loginToken / loginProvider / guestToken / deviceId / refreshToken / facebookId 字段的 CRUD
  *   - `clearAuthData()` 批量清空登录态
  *   - 所有方法返回 `Promise<Result<T>>`，与 Dart `Future<Result<T>>` 对齐
  */
 
 import type { Result } from "@/utils";
+import type { LoginStatus } from "@/data/dto/auth";
 
 export interface IAuthStorage {
   getLoginToken(): Promise<Result<string | null>>;
@@ -17,6 +18,10 @@ export interface IAuthStorage {
   hasLoginToken(): Promise<Result<boolean>>;
   clearLoginToken(): Promise<Result<void>>;
 
+  getLoginProvider(): Promise<Result<LoginStatus | null>>;
+  setLoginProvider(provider: LoginStatus): Promise<Result<void>>;
+  clearLoginProvider(): Promise<Result<void>>;
+
   getGuestToken(): Promise<Result<string | null>>;
   setGuestToken(token: string): Promise<Result<void>>;
   hasGuestToken(): Promise<Result<boolean>>;
diff --git a/src/data/storage/storage_keys.ts b/src/data/storage/storage_keys.ts
index 1ccb9f67..3450d8da 100644
--- a/src/data/storage/storage_keys.ts
+++ b/src/data/storage/storage_keys.ts
@@ -9,6 +9,7 @@
 export const StorageKeys = {
   // auth
   loginToken: "login_token",
+  loginProvider: "login_provider",
   guestToken: "guest_token",
   deviceId: "device_id",
   refreshToken: "refresh_token",
diff --git a/src/stores/auth/auth-actors.ts b/src/stores/auth/auth-actors.ts
index b189c58e..972509ec 100644
--- a/src/stores/auth/auth-actors.ts
+++ b/src/stores/auth/auth-actors.ts
@@ -235,7 +235,7 @@ export const guestLoginActor = fromPromise<LoginStatus, void>(async () => {
 //   1. deviceIdentifier.getDeviceId()     —— 无则生成 + 落盘
 //      （生产环境使用 fingerprintjs；非生产环境使用本地 UUID）
 //      （给后续 OAuth/email 登录准备 deviceId，不在 splash 首次访问就 auto-create 游客）
-//   2. AuthStorage.getLoginToken()         —— 有 → "email"
+//   2. AuthStorage.getLoginToken()         —— 有 → 读取 loginProvider，缺省回退 "email"
 //   3. AuthStorage.getFacebookId()         —— 有 → facebookIdLogin → "facebook"
 //   4. AuthStorage.getGuestToken()         —— 有 → "guest"
 //   5. 都没有 → "notLoggedIn"（让用户显式选 OAuth / Email / Guest 入口）
@@ -248,6 +248,10 @@ export const checkAuthStatusActor = fromPromise<LoginStatus, void>(async () => {
   // 2. 查 loginToken
   const loginTokenR = await storage.getLoginToken();
   if (loginTokenR.success && loginTokenR.data) {
+    const providerR = await storage.getLoginProvider();
+    if (providerR.success && isBusinessLoginProvider(providerR.data)) {
+      return providerR.data;
+    }
     return "email" as LoginStatus;
   }
 
@@ -281,3 +285,14 @@ export const checkAuthStatusActor = fromPromise<LoginStatus, void>(async () => {
   // 5. 都没有 → "notLoggedIn"（保持 splash 页面 + 登录入口）
   return "notLoggedIn" as LoginStatus;
 });
+
+function isBusinessLoginProvider(
+  provider: LoginStatus | null,
+): provider is LoginStatus {
+  return (
+    provider === "email" ||
+    provider === "facebook" ||
+    provider === "google" ||
+    provider === "apple"
+  );
+}