diff --git a/frontend/app.py b/frontend/app.py
index 4f6dac3..334f540 100644
--- a/frontend/app.py
+++ b/frontend/app.py
@@ -512,17 +512,18 @@ def _execute_sso_login(sso_url):
             except Exception as e:
                 logger.debug(f"跨域 URL 访问失败: {e}")
 
-        # Step 3: 只提取 weibo.com 域名的 Cookie（签到 API 只需要这些）
-        weibo_com_cookies = {}
+        # Step 3: 提取所有相关域名的 Cookie（weibo.com + sina.com.cn）
+        # 微博 SSO 需要两个域的 Cookie 配合才能保持长期有效
+        relevant_cookies = {}
         for cookie in sso_session.cookies:
-            if cookie.domain and 'weibo.com' in cookie.domain:
-                weibo_com_cookies[cookie.name] = cookie.value
+            if cookie.domain and ('weibo.com' in cookie.domain or 'sina.com.cn' in cookie.domain):
+                relevant_cookies[cookie.name] = cookie.value
 
-        cookie_str = '; '.join(f'{k}={v}' for k, v in weibo_com_cookies.items())
-        logger.info(f"weibo.com Cookie ({len(weibo_com_cookies)} 个): {list(weibo_com_cookies.keys())}")
+        cookie_str = '; '.join(f'{k}={v}' for k, v in relevant_cookies.items())
+        logger.info(f"收集到 Cookie ({len(relevant_cookies)} 个): {list(relevant_cookies.keys())}")
 
-        if not cookie_str or 'SUB' not in weibo_com_cookies:
-            logger.error(f"Cookie 不完整，缺少 SUB。获取到: {list(weibo_com_cookies.keys())}")
+        if not cookie_str or 'SUB' not in relevant_cookies:
+            logger.error(f"Cookie 不完整，缺少 SUB。获取到: {list(relevant_cookies.keys())}")
             return None, None, None
 
         if not uid: