diff --git a/platform-common/src/main/java/com/lyms/platform/common/utils/JsonUtil.java b/platform-common/src/main/java/com/lyms/platform/common/utils/JsonUtil.java
index 7e00299..0f2b619 100644
--- a/platform-common/src/main/java/com/lyms/platform/common/utils/JsonUtil.java
+++ b/platform-common/src/main/java/com/lyms/platform/common/utils/JsonUtil.java
@@ -77,6 +77,9 @@ public class JsonUtil {
 
     public static String obj2JsonString(Object obj) {
         try {
+            if(obj==null){
+                return null;
+            }
             return JSONObject.fromObject(obj).toString();
         } catch (Exception e) {
             ExceptionUtils.catchException(e, "obj2 json string error ." + e.getMessage());