diff --git a/safety-eval-domain/src/main/java/org/qinan/safetyeval/domain/constant/QualificationLevelEnum.java b/safety-eval-domain/src/main/java/org/qinan/safetyeval/domain/constant/QualificationLevelEnum.java
index 42d6bce4..97c15424 100644
--- a/safety-eval-domain/src/main/java/org/qinan/safetyeval/domain/constant/QualificationLevelEnum.java
+++ b/safety-eval-domain/src/main/java/org/qinan/safetyeval/domain/constant/QualificationLevelEnum.java
@@ -10,11 +10,13 @@ public enum QualificationLevelEnum {
     SENIOR("SENIOR", "高级"),
     MIDDLE("MIDDLE", "中级"),
     JUNIOR("JUNIOR", "初级"),
+    NONE("NONE", "无"),
     ;
 
     public static final String SENIOR_ONE = "一级";
     public static final String MIDDLE_TWO = "二级";
     public static final String JUNIOR_THREE = "三级";
+    public static final String NONE_LEVEL = "无";
 
     private final String code;
     private final String name;
@@ -43,7 +45,7 @@ public enum QualificationLevelEnum {
         if (name.contains(JUNIOR_THREE)) {
             return JUNIOR;
         }
-        return null;
+        return NONE;
     }
 
     public String getCode() {
@@ -56,13 +58,13 @@ public enum QualificationLevelEnum {
 
     public static QualificationLevelEnum ofCode(String code) {
         if (code == null) {
-            return null;
+            return NONE;
         }
         for (QualificationLevelEnum item : values()) {
             if (Objects.equals(item.code, code)) {
                 return item;
             }
         }
-        return null;
+        return NONE;
     }
 }