diff --git a/fe/fe-core/src/main/java/org/apache/doris/common/util/PrintableMap.java b/fe/fe-core/src/main/java/org/apache/doris/common/util/PrintableMap.java
index 33e5624a51..27d6468827 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/common/util/PrintableMap.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/common/util/PrintableMap.java
@@ -93,6 +93,9 @@ public class PrintableMap<K, V> {
 
     @Override
     public String toString() {
+        if (map == null) {
+            return "";
+        }
         StringBuilder sb = new StringBuilder();
         Iterator<Map.Entry<K, V>> iter = showEntries().iterator();
         while (iter.hasNext()) {