diff --git a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheManager.java b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheManager.java
index dd1b4f9b5f..afe540d2f1 100644
--- a/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheManager.java
+++ b/hugegraph-server/hugegraph-core/src/main/java/org/apache/hugegraph/backend/cache/CacheManager.java
@@ -56,7 +56,7 @@ public static boolean cacheEnableMetrics(String name, boolean enabled) {
         return cache.enableMetrics(enabled);
     }
 
-    public CacheManager() {
+    private CacheManager() {
         this.caches = new ConcurrentHashMap<>();
         this.timer = new Timer("cache-expirer", true);