diff --git a/Service/Cloud/Client/CloudClient.cs b/Service/Cloud/Client/CloudClient.cs
index 95b65f4..72591b3 100644
--- a/Service/Cloud/Client/CloudClient.cs
+++ b/Service/Cloud/Client/CloudClient.cs
@@ -554,7 +554,7 @@ public class CloudClient : IMqttClientConnectedHandler, IMqttApplicationMessageR
         ChargeRecordUpLoad req = new ChargeRecordUpLoad()
         {
             chrsn = chargeOrder.CloudChargeOrder,
-            son = swapOrder.CloudSn,
+            son = swapOrder?.CloudSn,
             bid = chargeOrder.BatteryNo,
             st = chargeOrder.StartTime ?? DateTime.Now,
             et = lastChargeOrder.EndTime ?? DateTime.Now,