diff --git a/YD_AllHeartRates.Api/Mqtt/MqttBackgroundService.cs b/YD_AllHeartRates.Api/Mqtt/MqttBackgroundService.cs
index 0cfb42f..c8bae0a 100644
--- a/YD_AllHeartRates.Api/Mqtt/MqttBackgroundService.cs
+++ b/YD_AllHeartRates.Api/Mqtt/MqttBackgroundService.cs
@@ -256,7 +256,7 @@ namespace YD_AllHeartRates.Api.Mqtt
                         totalData.ScoreTime = jumpData.ScoreTime;
 
                         // 写入缓存（总值 + 原始值）
-                        _caching.AddObject(jumpKey, totalData, 60 * 24);
+                        _caching.AddObject(jumpKey, totalData, 28800);
                         _caching.AddObject(rawKey, jumpData, 60);
 
                         // 记录活跃学生编号（便于定时入库）