diff --git a/liteflow-core/src/main/java/com/yomahub/liteflow/core/FlowExecutor.java b/liteflow-core/src/main/java/com/yomahub/liteflow/core/FlowExecutor.java
index fe2a83c8a..d09bf88ae 100644
--- a/liteflow-core/src/main/java/com/yomahub/liteflow/core/FlowExecutor.java
+++ b/liteflow-core/src/main/java/com/yomahub/liteflow/core/FlowExecutor.java
@@ -111,8 +111,6 @@ public class FlowExecutor {
 	
 	public LiteflowResponse<Slot> execute(String chainId, Object param, Class<? extends Slot> slotClazz, Integer slotIndex,
 									boolean isInnerChain) throws Exception {
-		Slot slot = null;
-
 		if (FlowBus.needInit()) {
 			init();
 		}
@@ -133,8 +131,8 @@ public class FlowExecutor {
 			throw new NoAvailableSlotException("there is no available slot");
 		}
 
-		slot = DataBus.getSlot(slotIndex);
-		if (slot == null) {
+		Slot slot = DataBus.getSlot(slotIndex);
+		if (ObjectUtil.isNull(slot)) {
 			throw new NoAvailableSlotException("the slot is not exist");
 		}