diff --git a/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/domain/model/dataset/Dataset.java b/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/domain/model/dataset/Dataset.java
index 6ded0ebf9..304702d0e 100644
--- a/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/domain/model/dataset/Dataset.java
+++ b/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/domain/model/dataset/Dataset.java
@@ -72,6 +72,7 @@ public class Dataset extends BaseEntity<String> {
     /**
      * 额外元数据，JSON格式
      */
+    @TableField(typeHandler = PgJsonTypeHandler.class)
     private String metadata;
     /**
      * 数据集状态
diff --git a/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/interfaces/dto/AddFilesRequest.java b/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/interfaces/dto/AddFilesRequest.java
index 094510bdb..66fdde475 100644
--- a/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/interfaces/dto/AddFilesRequest.java
+++ b/backend/services/data-management-service/src/main/java/com/datamate/datamanagement/interfaces/dto/AddFilesRequest.java
@@ -12,6 +12,7 @@
 import org.apache.commons.collections4.CollectionUtils;
 import org.apache.commons.lang3.StringUtils;
 
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
@@ -43,7 +44,7 @@ public static class FileRequest {
         @Size(max = 1000, message = "文件路径长度不能超过1000个字符")
         private String filePath;
 
-        private Map<String, Object> metadata;
+        private Map<String, Object> metadata = new HashMap<>();
     }
 
     private boolean softAdd;