diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/types/DataType.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/types/DataType.java
index c939786237..8f88732621 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/types/DataType.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/types/DataType.java
@@ -350,7 +350,7 @@ public abstract class DataType {
         } else if (type.isStructType()) {
             List<StructField> structFields = ((org.apache.doris.catalog.StructType) (type)).getFields().stream()
                     .map(cf -> new StructField(cf.getName(), fromCatalogType(cf.getType()),
-                            cf.getContainsNull(), cf.getComment()))
+                            cf.getContainsNull(), cf.getComment() == null ? "" : cf.getComment()))
                     .collect(ImmutableList.toImmutableList());
             return new StructType(structFields);
         } else if (type.isMapType()) {