diff --git a/mongodbwriter/doc/mongodbwriter.md b/mongodbwriter/doc/mongodbwriter.md
index 81e6516..93f5029 100644
--- a/mongodbwriter/doc/mongodbwriter.md
+++ b/mongodbwriter/doc/mongodbwriter.md
@@ -116,10 +116,10 @@ MongoDBWriter通过Datax框架获取Reader生成的数据，然后将Datax支持
                                 "type": "int"
                             }
                         ],
-			"writeMode": {
-				"isReplace": "true",
-				"replaceKey": "unique_id"
-			}
+                      "writeMode": {
+                        "isReplace": "true",
+                        "replaceKey": "unique_id"
+                      }
                     }
                 }
             }