diff --git a/jero-boot/jero-cloud-module/jero-cloud-xxljob/src/main/java/com/xxl/job/admin/core/util/LocalCacheUtil.java b/jero-boot/jero-cloud-module/jero-cloud-xxljob/src/main/java/com/xxl/job/admin/core/util/LocalCacheUtil.java
index fbab0613..cd0124ad 100644
--- a/jero-boot/jero-cloud-module/jero-cloud-xxljob/src/main/java/com/xxl/job/admin/core/util/LocalCacheUtil.java
+++ b/jero-boot/jero-cloud-module/jero-cloud-xxljob/src/main/java/com/xxl/job/admin/core/util/LocalCacheUtil.java
@@ -1,5 +1,7 @@
 package com.xxl.job.admin.core.util;
 
+import java.util.Map;
+import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 
@@ -9,6 +11,8 @@ import java.util.concurrent.ConcurrentMap;
  * @author xuxueli 2018-01-22 21:37:34
  */
 public class LocalCacheUtil {
+    private LocalCacheUtil() {
+    }
 
     private static ConcurrentMap<String, LocalCacheData> cacheRepository = new ConcurrentHashMap<String, LocalCacheData>();   // 类型建议用抽象父类，兼容性更好；
     private static class LocalCacheData{
@@ -120,10 +124,11 @@ public class LocalCacheUtil {
      */
     public static boolean cleanTimeoutCache(){
         if (!cacheRepository.keySet().isEmpty()) {
-            for (String key: cacheRepository.keySet()) {
-                LocalCacheData localCacheData = cacheRepository.get(key);
+            Set<Map.Entry<String, LocalCacheData>> entries = cacheRepository.entrySet();
+            for (Map.Entry<String, LocalCacheData> e :entries) {
+                LocalCacheData localCacheData = e.getValue();
                 if (localCacheData!=null && System.currentTimeMillis()>=localCacheData.getTimeoutTime()) {
-                    cacheRepository.remove(key);
+                    cacheRepository.remove(e.getKey());
                 }
             }
         }