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 0293f4058..909504009 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
@@ -288,6 +288,10 @@ public class FlowExecutor {
 
     public <T extends Slot> T execute(String chainId, Object param, Class<T> slotClazz,
                                       Integer slotIndex, boolean isInnerChain) throws Exception {
+        if (null == param) {
+            //data slot is a ConcurrentHashMap, so null value will trigger NullPointerException
+            throw new NullParamException("data slot cann't accept null param");
+        }
         T slot = this.doExecute(chainId, param, slotClazz, slotIndex, isInnerChain);
         if (ObjectUtil.isNotNull(slot.getException())) {
             throw slot.getException();
@@ -309,7 +313,10 @@ public class FlowExecutor {
     public <T extends Slot> LiteflowResponse<T> execute2Resp(String chainId, Object param, Class<T> slotClazz, Integer slotIndex,
                                                              boolean isInnerChain) {
         LiteflowResponse<T> response = new LiteflowResponse<>();
-
+        if (null == param) {
+            //data slot is a ConcurrentHashMap, so null value will trigger NullPointerException
+            throw new NullParamException("data slot cann't accept null param");
+        }
         T slot = doExecute(chainId, param, slotClazz, slotIndex, isInnerChain);
 
         if (ObjectUtil.isNotNull(slot.getException()) && !notFailExceptionList.contains(slot.getException().getClass())) {
diff --git a/liteflow-core/src/main/java/com/yomahub/liteflow/entity/data/AbsSlot.java b/liteflow-core/src/main/java/com/yomahub/liteflow/entity/data/AbsSlot.java
index f2f95132a..e2255e6a5 100644
--- a/liteflow-core/src/main/java/com/yomahub/liteflow/entity/data/AbsSlot.java
+++ b/liteflow-core/src/main/java/com/yomahub/liteflow/entity/data/AbsSlot.java
@@ -7,6 +7,7 @@
  */
 package com.yomahub.liteflow.entity.data;
 
+import com.yomahub.liteflow.exception.NullParamException;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import java.util.Iterator;
@@ -56,10 +57,18 @@ public abstract class AbsSlot implements Slot {
 	}
 
 	public <T> void setInput(String nodeId,T t){
+		if (null == t) {
+			//data slot is a ConcurrentHashMap, so null value will trigger NullPointerException
+			throw new NullParamException("data slot cann't accept null param");
+		}
 		dataMap.put(NODE_INPUT_PREFIX + nodeId, t);
 	}
 
 	public <T> void setOutput(String nodeId,T t){
+		if (null == t) {
+			//data slot is a ConcurrentHashMap, so null value will trigger NullPointerException
+			throw new NullParamException("data slot cann't accept null param");
+		}
 		dataMap.put(NODE_OUTPUT_PREFIX + nodeId, t);
 	}
 
diff --git a/liteflow-core/src/main/java/com/yomahub/liteflow/exception/NullParamException.java b/liteflow-core/src/main/java/com/yomahub/liteflow/exception/NullParamException.java
new file mode 100644
index 000000000..295555ac5
--- /dev/null
+++ b/liteflow-core/src/main/java/com/yomahub/liteflow/exception/NullParamException.java
@@ -0,0 +1,31 @@
+package com.yomahub.liteflow.exception;
+
+import java.io.Serializable;
+
+/**
+ * null param exception
+ * when param is null, dataMap (ConcurrentHashMap) cann't accept a null value
+ *
+ * @Author LeoLee
+ * @Date 2021/12/10 16:47
+ * @Version 1.0
+ */
+public class NullParamException extends RuntimeException implements Serializable {
+
+    private static final long serialVersionUID = -864259139568071245L;
+
+    private String message;
+
+    public NullParamException(String message) {
+        this.message = message;
+    }
+
+    @Override
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+}