diff --git a/Demo.md b/Demo.md
index b1b2d22..61ac207 100644
--- a/Demo.md
+++ b/Demo.md
@@ -1,3 +1,8 @@
+前置依赖`three`,`xaop`
+
+`npm i three xaop`
+
+
 ```
 
 import { Polyline } from "webcad-api";