diff --git a/docs/source/component/backbone.md b/docs/source/component/backbone.md
index de77f85ec..0e600dbb8 100644
--- a/docs/source/component/backbone.md
+++ b/docs/source/component/backbone.md
@@ -1294,6 +1294,23 @@ message InputLayer {
 - `wide_output_dim` wide模型每个特征的参数权重维度，一般设定为1
 - `concat_seq_feature` 是否需要把序列特征的embedding拼接在一起
 
+比如同一个group的所有特征 pooling 为一个特征的示例如下：
+
+- 前提条件：这个group内的所有特征的在embedding_dim都相同
+
+```protobuf
+blocks {
+  name: 'feat_pooling'
+  inputs {
+    feature_group_name: 'feat_group'
+  }
+  input_layer {
+    only_output_3d_tensor: true
+  }
+  extra_input_fn: 'lambda x: tf.reduce_sum(x, axis=1)'
+}
+```
+
 ## 3. Lambda组件块
 
 `Lambda组件块`可以配置一个lambda函数，执行一些较简单的操作。示例如下：
diff --git a/docs/source/component/sequence.md b/docs/source/component/sequence.md
index ddcbace7d..c048ed74a 100644
--- a/docs/source/component/sequence.md
+++ b/docs/source/component/sequence.md
@@ -73,6 +73,43 @@ blocks {
 }
 ```
 
+## 对输入序列pooling的例子
+
+```protobuf
+model_config: {
+  model_name: 'SumPooling'
+  model_class: 'RankModel
+  ...
+  feature_groups: {
+    group_name: 'sequence'
+    feature_names: "tag_category_list"
+    feature_names: "tag_brand_list"
+    wide_deep: DEEP
+  }
+  backbone {
+
+    blocks {
+      name: 'seq_input'
+      inputs {
+        feature_group_name: 'sequence'
+      }
+      input_layer {
+        output_seq_and_normal_feature: true
+      }
+    }
+    blocks {
+      name: 'sum_pooling'
+      inputs {
+        block_name: 'seq_input'
+        input_slice: '[0]'
+      }
+      extra_input_fn: 'lambda x: tf.reduce_sum(x, axis=1)'
+    }
+    ...
+  }
+}
+```
+
 ## 完整的例子
 
 - [DIN](../models/din.md)