diff --git a/zc-business/src/main/java/com/zc/business/controller/DcDeviceOnlineController.java b/zc-business/src/main/java/com/zc/business/controller/DcDeviceOnlineController.java
index 1211d7c1..52e08c39 100644
--- a/zc-business/src/main/java/com/zc/business/controller/DcDeviceOnlineController.java
+++ b/zc-business/src/main/java/com/zc/business/controller/DcDeviceOnlineController.java
@@ -238,12 +238,15 @@ public class DcDeviceOnlineController extends BaseController {
         LocalDate startDate = LocalDate.now().minusDays(30);
         LocalDate endDate = LocalDate.now();
         List<OnlineSum> onlineSums = onlineSumService.queryByDateRangeOfDevice(deviceId, startDate, endDate);
+        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
         if (onlineSums.isEmpty()) {
             return AjaxResult.success(UniversalEnum.NO_DATA_AVAILABLE.getValue());
         }
         Map<String, Object> map = new HashMap<>();
         for (OnlineSum onlineSum : onlineSums) {
-            map.put(onlineSum.getStatisticalDate().toString(), onlineSum.getOnlineRate());
+            LocalDateTime dateTime = onlineSum.getStatisticalDate();
+            String formattedDate = dateTime.format(formatter);
+            map.put(formattedDate, onlineSum.getOnlineRate());
         }
         return AjaxResult.success(new TreeMap<>(map));
     }
@@ -584,4 +587,4 @@ public class DcDeviceOnlineController extends BaseController {
         }
     }
 
-}
\ No newline at end of file
+}