diff --git a/flink-doris-connector/src/main/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBType.java b/flink-doris-connector/src/main/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBType.java
index cb4896ab2..9fa7b540f 100644
--- a/flink-doris-connector/src/main/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBType.java
+++ b/flink-doris-connector/src/main/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBType.java
@@ -62,7 +62,7 @@ public static String toDorisType(Object value) {
         } else if (value instanceof String) {
             return DorisType.STRING;
         } else if (value instanceof ObjectId) {
-            return DorisType.VARCHAR + "(30)";
+            return DorisType.VARCHAR + "(36)";
         } else if (value instanceof List) {
             return DorisType.ARRAY + "<" + DorisType.STRING + ">";
         } else if (value instanceof Decimal128) {
diff --git a/flink-doris-connector/src/test/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBSchemaTest.java b/flink-doris-connector/src/test/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBSchemaTest.java
index 2f0956084..9a4a9eb73 100644
--- a/flink-doris-connector/src/test/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBSchemaTest.java
+++ b/flink-doris-connector/src/test/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBSchemaTest.java
@@ -69,7 +69,7 @@ public void testMongoSampleDataFields() throws Exception {
         MongoDBSchema mongoDBSchema = new MongoDBSchema(sampleData, "db_TEST", "test_table", "");
 
         assertEquals(
-                "{_id=FieldSchema{name='_id', typeString='VARCHAR(30)', defaultValue='null', comment='null'}, c_string=FieldSchema{name='c_string', typeString='STRING', defaultValue='null', comment='null'}, c_bool=FieldSchema{name='c_bool', typeString='BOOLEAN', defaultValue='null', comment='null'}, c_int=FieldSchema{name='c_int', typeString='INT', defaultValue='null', comment='null'}, c_long=FieldSchema{name='c_long', typeString='BIGINT', defaultValue='null', comment='null'}, c_double=FieldSchema{name='c_double', typeString='DECIMALV3(5,2)', defaultValue='null', comment='null'}, c_decimal=FieldSchema{name='c_decimal', typeString='DECIMALV3(7,2)', defaultValue='null', comment='null'}, c_date=FieldSchema{name='c_date', typeString='DATETIMEV2(3)', defaultValue='null', comment='null'}, c_timestamp=FieldSchema{name='c_timestamp', typeString='DATETIMEV2(0)', defaultValue='null', comment='null'}, c_object=FieldSchema{name='c_object', typeString='STRING', defaultValue='null', comment='null'}, c_array=FieldSchema{name='c_array', typeString='ARRAY<STRING>', defaultValue='null', comment='null'}}",
+                "{_id=FieldSchema{name='_id', typeString='VARCHAR(36)', defaultValue='null', comment='null'}, c_string=FieldSchema{name='c_string', typeString='STRING', defaultValue='null', comment='null'}, c_bool=FieldSchema{name='c_bool', typeString='BOOLEAN', defaultValue='null', comment='null'}, c_int=FieldSchema{name='c_int', typeString='INT', defaultValue='null', comment='null'}, c_long=FieldSchema{name='c_long', typeString='BIGINT', defaultValue='null', comment='null'}, c_double=FieldSchema{name='c_double', typeString='DECIMALV3(5,2)', defaultValue='null', comment='null'}, c_decimal=FieldSchema{name='c_decimal', typeString='DECIMALV3(7,2)', defaultValue='null', comment='null'}, c_date=FieldSchema{name='c_date', typeString='DATETIMEV2(3)', defaultValue='null', comment='null'}, c_timestamp=FieldSchema{name='c_timestamp', typeString='DATETIMEV2(0)', defaultValue='null', comment='null'}, c_object=FieldSchema{name='c_object', typeString='STRING', defaultValue='null', comment='null'}, c_array=FieldSchema{name='c_array', typeString='ARRAY<STRING>', defaultValue='null', comment='null'}}",
                 mongoDBSchema.getFields().toString());
     }
 
diff --git a/flink-doris-connector/src/test/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBTypeTest.java b/flink-doris-connector/src/test/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBTypeTest.java
index 4e273ab85..2701dd9a6 100644
--- a/flink-doris-connector/src/test/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBTypeTest.java
+++ b/flink-doris-connector/src/test/java/org/apache/doris/flink/tools/cdc/mongodb/MongoDBTypeTest.java
@@ -55,7 +55,7 @@ public void toDorisType() {
         assertEquals(DorisType.BOOLEAN, MongoDBType.toDorisType(new Boolean(true)));
         assertEquals(DorisType.STRING, MongoDBType.toDorisType("string"));
         assertEquals(
-                DorisType.VARCHAR + "(30)",
+                DorisType.VARCHAR + "(36)",
                 MongoDBType.toDorisType(new ObjectId("66583533791a67a6f8c5a339")));
         assertEquals(
                 "DECIMALV3(10,5)",