diff --git a/docs/部署指南.md b/docs/部署指南.md
index 7d106ce..3051f85 100644
--- a/docs/部署指南.md
+++ b/docs/部署指南.md
@@ -158,6 +158,16 @@ Images/Placeholder/defaultAvatar.png
 Images/Placeholder/weixin.png
 ```
 
+这三张图是**必需的**，缺了会导致「我的」页头像位、「登录」页背景显示为裂图。
+验证：
+
+```bash
+curl -o /dev/null -s -w "%{http_code}\n" https://<数据域名>/Images/Placeholder/user.png
+curl -o /dev/null -s -w "%{http_code}\n" https://<数据域名>/Images/Placeholder/weixin.png
+```
+
+两条都返回 `200` 才算就绪。
+
 **目录名与文件名不可更改**，前端是拼路径访问的。完整约定见
 [`yelaymaths_data.yeomai.site/README.md`](../yelaymaths_data.yeomai.site/README.md)。
 
diff --git a/yelaymaths_api/src/modules/auth/auth.service.ts b/yelaymaths_api/src/modules/auth/auth.service.ts
index 75a90f1..0509042 100644
--- a/yelaymaths_api/src/modules/auth/auth.service.ts
+++ b/yelaymaths_api/src/modules/auth/auth.service.ts
@@ -3,6 +3,7 @@ import { JwtService } from '@nestjs/jwt';
 import { APP_CONFIG, type AppConfig } from '../../config/config';
 import { encryptSecret } from '../../common/crypto';
 import { AppError } from '../../common/errors';
+import { staticUrls } from '../../common/urls';
 import { PrismaService } from '../../prisma/prisma.service';
 import { WechatService } from './wechat.service';
 
@@ -10,10 +11,23 @@ import { WechatService } from './wechat.service';
 export const ACCESS_TTL = '2h' as const;
 export const REFRESH_TTL = '30d' as const;
 
+/**
+ * 登录返回的用户信息。
+ *
+ * 字段必须与 GET /v1/me 保持一致（尤其是 headiconUrl）——
+ * 小程序启动时只调登录接口，若这里少字段，页面读到的就是残缺的 user，
+ * 头像会退回占位图，直到用户手动点一次登录调了 /v1/me 才恢复。
+ */
 export interface LoginResult {
   accessToken: string;
   refreshToken: string;
-  user: { id: number; nickname: string | null; headiconId: number; isNew: boolean };
+  user: {
+    id: number;
+    nickname: string | null;
+    headiconId: number;
+    headiconUrl: string | null;
+    isNew: boolean;
+  };
 }
 
 @Injectable()
@@ -55,7 +69,15 @@ export class AuthService {
     return {
       accessToken: await this.sign(user.id, 'user', ACCESS_TTL, this.cfg.JWT_ACCESS_SECRET),
       refreshToken: await this.sign(user.id, 'user', REFRESH_TTL, this.cfg.JWT_REFRESH_SECRET),
-      user: { id: user.id, nickname: user.nickname, headiconId: user.headicon_id, isNew: !existing },
+      user: {
+        id: user.id,
+        nickname: user.nickname,
+        headiconId: user.headicon_id,
+        // 与 /v1/me 的规则一致：0 表示未设置，交给前端用占位图
+        headiconUrl:
+          user.headicon_id > 0 ? staticUrls.headicon(this.cfg.STATIC_BASE_URL, user.headicon_id) : null,
+        isNew: !existing,
+      },
     };
   }