diff --git a/db/stats_db.py b/db/stats_db.py
index 49efba7..dd82e28 100644
--- a/db/stats_db.py
+++ b/db/stats_db.py
@@ -442,9 +442,9 @@ class StatsDBOperator(BaseDBOperator):
         WHERE stat_date >= %s
         """
         success_rate_result = self.execute_query(success_rate_sql, (start_date_str,), fetch_one=True)
-        success_rate = 0
+        success_rate = 0.0
         if success_rate_result and success_rate_result['total_calls']:
-            success_rate = (success_rate_result['success_calls'] / success_rate_result['total_calls']) * 100
+            success_rate = float((success_rate_result['success_calls'] / success_rate_result['total_calls']) * 100)
         
         # 3. 活跃用户数
         active_users_sql = """
@@ -489,7 +489,9 @@ class StatsDBOperator(BaseDBOperator):
         WHERE stat_date >= %s
         """
         avg_response_time_result = self.execute_query(avg_response_time_sql, (start_date_str,), fetch_one=True)
-        avg_response_time = avg_response_time_result['avg_response_time'] if avg_response_time_result and avg_response_time_result['avg_response_time'] else 0
+        avg_response_time = float(
+            avg_response_time_result['avg_response_time']
+        ) if avg_response_time_result and avg_response_time_result['avg_response_time'] else 0.0
 
         # 6.1 群渗透率（活跃群内，触发人数 / 群成员数 的均值）
         group_penetration_sql = """