diff --git a/readme.md b/readme.md
index 62746a3a..67a2baf3 100644
--- a/readme.md
+++ b/readme.md
@@ -44,7 +44,7 @@
         - [Airbnb召回](ch02/ch2.1/ch2.1.2/Airbnb)
     - [YoutubeDNN召回](docs/ch02/ch2.1/ch2.1.2/YoutubeDNN.md)
     - **双塔召回**
-        - 经典双塔
+        - [经典双塔](docs/ch02/ch2.1/ch2.1.2/DSSM.md)
         - [Youtube双塔](docs/ch02/ch2.1/ch2.1.2/YoutubeTwoTower.md)
     - **图召回**
         - [EGES](docs/ch02/ch2.1/ch2.1.3/EGES.md)