diff --git a/Sync-ES.md b/Sync-ES.md
index 2552981..68248cc 100644
--- a/Sync-ES.md
+++ b/Sync-ES.md
@@ -208,6 +208,74 @@ left join (select user_id, group_concat(label order by id desc separator ';') as
 objFields:
   labels: array:;
 ```
+- 父子文档索引
+
+es/customer.yml
+```
+......
+esMapping:
+  _index: customer
+  _type: _doc
+  _id: id
+  relations:
+    customer_order:
+      name: customer
+  sql: "select t.id, t.name, t.email from customer t"
+```
+es/order.yml
+```
+esMapping:
+  _index: customer
+  _type: _doc
+  _id: _id
+  relations:
+    customer_order:
+      name: order
+      parent: customer_id
+  sql: "select concat('oid_', t.id) as _id,
+        t.customer_id,
+        t.id as order_id,
+        t.serial_code as order_serial,
+        t.c_time as order_time
+        from biz_order t"
+  skips:
+    - customer_id
+```
+mapping示例:
+```
+{
+  "mappings":{
+    "_doc":{
+      "properties":{
+        "id": {
+          "type": "long"
+        },
+        "name": {
+          "type": "text"
+        },
+        "email": {
+          "type": "text"
+        },
+        "order_id": {
+          "type": "long"
+        },
+        "order_serial": {
+          "type": "text"
+        },
+        "order_time": {
+          "type": "date"
+        },
+        "customer_order":{
+          "type":"join",
+          "relations":{
+            "customer":"order"
+          }
+        }
+      }
+    }
+  }
+}
+```
 
 ### 3 启动ES数据同步
 #### 启动canal-adapter启动器