diff --git a/externals/instruction.md b/externals/instruction.md
index 8527a91..f60a8a2 100644
--- a/externals/instruction.md
+++ b/externals/instruction.md
@@ -12,3 +12,24 @@ or equivalent Markdown code
 [![996.icu](https://img.shields.io/badge/link-996.icu-red.svg)](https://996.icu)
 ```
 <a href="https://996.icu"><img src="https://img.shields.io/badge/link-996.icu-red.svg" alt="996.icu"></a>
+
+Add License
+---
+#### Budget
+Markdown code for badget：
+```markdown
+[![LICENSE](https://img.shields.io/badge/license-NPL%20(The%20996%20Prohibited%20License)-blue.svg)](https://github.com/996icu/996.ICU/blob/master/LICENSE)
+```
+[![LICENSE](https://img.shields.io/badge/license-NPL%20(The%20996%20Prohibited%20License)-blue.svg)](https://github.com/996icu/996.ICU/blob/master/LICENSE)
+
+#### License file
+The 996ICU license is designed for multi-licensing, you can use it with other licenses like MIT in these ways:
+- Separate license files:
+  - In `LICENSE` file, list all licenses you used with `AND`.
+  - Add `LICENSE.996ICU` or `LINCES.NPL` file for details of 996ICU license.
+  - Add `LINCESE.MIT` file for details of MIT license.
+- Single license files:
+  - Add primary license content, such as MIT license.
+  - Add separation line like `----------`.
+  - Add 996ICU license content.
+