diff --git a/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/queue/StandByTaskInstancePriorityQueue.java b/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/queue/StandByTaskInstancePriorityQueue.java
index c11c4fe5a9..d02c5715e3 100644
--- a/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/queue/StandByTaskInstancePriorityQueue.java
+++ b/dolphinscheduler-service/src/main/java/org/apache/dolphinscheduler/service/queue/StandByTaskInstancePriorityQueue.java
@@ -36,16 +36,10 @@ import com.google.common.base.Preconditions;
  */
 public class StandByTaskInstancePriorityQueue implements TaskPriorityQueue<TaskInstance> {
 
-    /**
-     * queue size
-     */
-    private static final Integer QUEUE_MAX_SIZE = 3000;
-
     /**
      * queue
      */
-    private final PriorityQueue<TaskInstance> queue =
-            new PriorityQueue<>(QUEUE_MAX_SIZE, new TaskInstancePriorityComparator());
+    private final PriorityQueue<TaskInstance> queue = new PriorityQueue<>(new TaskInstancePriorityComparator());
     private final Set<String> taskInstanceIdentifySet = Collections.synchronizedSet(new HashSet<>());
 
     /**