diff --git a/milvus/utils/Format.ts b/milvus/utils/Format.ts
index 86eac69a..6c7ccf8b 100644
--- a/milvus/utils/Format.ts
+++ b/milvus/utils/Format.ts
@@ -449,7 +449,7 @@ export const buildFieldDataMap = (fields_data: any[]) => {
       if (key === 'array_data') {
         field_data = field_data.map((f: any) => {
           const key = f.data;
-          return f[key].data;
+          return key ? f[key].data: [];
         });
       }
 
diff --git a/test/grpc/Insert.spec.ts b/test/grpc/Insert.spec.ts
index a010a456..08bf8b1f 100644
--- a/test/grpc/Insert.spec.ts
+++ b/test/grpc/Insert.spec.ts
@@ -292,12 +292,11 @@ describe(`Insert API`, () => {
   });
 
   it(`Insert Data on float field expect success`, async () => {
-    const vectorsData = generateInsertData(COLLECTION_NAME_PARAMS.fields, 10);
-
+    const dataToInsert = generateInsertData(COLLECTION_NAME_PARAMS.fields, 10);
     const params: InsertReq = {
       collection_name: COLLECTION_NAME,
       partition_name: PARTITION_NAME,
-      fields_data: vectorsData,
+      fields_data: dataToInsert,
     };
 
     const res = await milvusClient.insert(params);
@@ -310,7 +309,7 @@ describe(`Insert API`, () => {
       expr: 'id > 0',
       output_fields: ['json', 'id', 'varChar_array'],
     });
-    // console.log('query', query);
+     // console.log('query', query.data);
     expect(query.status.error_code).toEqual(ErrorCode.SUCCESS);
 
     const search = await milvusClient.search({
diff --git a/test/tools/data.ts b/test/tools/data.ts
index b1cfc913..f8e3342d 100644
--- a/test/tools/data.ts
+++ b/test/tools/data.ts
@@ -120,6 +120,12 @@ export const genBinaryVector: DataGenerator = params => {
  */
 export const genArray: DataGenerator = params => {
   const { element_type, max_capacity = 0 } = params!;
+
+  // half chance to generate empty array
+  if (Math.random() > 0.5) {
+    return [];
+  }
+
   return Array.from({ length: max_capacity! }, () => {
     return dataGenMap[element_type!](params);
   });