diff --git a/um_wasm/README.md b/um_wasm/README.md
index 9d7ceb8..8f92350 100644
--- a/um_wasm/README.md
+++ b/um_wasm/README.md
@@ -1,3 +1,12 @@
 # um_wasm
 
 加解密算法 Rust ❤️ WebAssembly 计划。
+
+## 构建
+
+回到 `um_wasm_loader`，运行 `build.js` 构建。
+
+```shell
+cd um_wasm_loader
+node build.js
+```