diff --git a/email_service.py b/email_service.py
index a070cee..a4289cf 100644
--- a/email_service.py
+++ b/email_service.py
@@ -33,6 +33,24 @@ import db_pool
 from crypto_utils import encrypt_password, decrypt_password, is_encrypted
 
 
+def parse_datetime(dt_str: str) -> datetime:
+    """解析数据库中的时间字符串，支持带微秒和不带微秒的格式"""
+    if not dt_str:
+        return datetime.min
+    # 尝试多种格式
+    formats = [
+        '%Y-%m-%d %H:%M:%S.%f',  # 带微秒
+        '%Y-%m-%d %H:%M:%S',      # 不带微秒
+    ]
+    for fmt in formats:
+        try:
+            return datetime.strptime(dt_str, fmt)
+        except ValueError:
+            continue
+    # 如果都失败，返回最小时间（视为过期）
+    return datetime.min
+
+
 # ============ 常量配置 ============
 
 # 邮件类型
@@ -1062,7 +1080,7 @@ def verify_email_token(token: str, token_type: str) -> Optional[Dict[str, Any]]:
             return None
 
         # 检查是否过期
-        if datetime.strptime(expires_at, '%Y-%m-%d %H:%M:%S') < datetime.now():
+        if parse_datetime(expires_at) < datetime.now():
             return None
 
         # 标记为已使用
@@ -1100,7 +1118,7 @@ def check_rate_limit(email: str, token_type: str) -> bool:
         if not row:
             return True
 
-        last_sent = datetime.strptime(row[0], '%Y-%m-%d %H:%M:%S')
+        last_sent = parse_datetime(row[0])
         elapsed = (datetime.now() - last_sent).total_seconds()
 
         return elapsed >= limit_seconds
@@ -1376,7 +1394,7 @@ def verify_password_reset_token(token: str) -> Optional[Dict[str, Any]]:
             return None
 
         # 检查是否过期
-        if datetime.strptime(expires_at, '%Y-%m-%d %H:%M:%S') < datetime.now():
+        if parse_datetime(expires_at) < datetime.now():
             return None
 
         return {'user_id': user_id, 'email': email, 'token_id': token_id}