diff --git a/docs/api.md b/docs/api.md
index f2f41b0..5a5f170 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -63,6 +63,15 @@ query param
 
 SiweMessage说明: https://docs.login.xyz/sign-in-with-ethereum/quickstart-guide/creating-siwe-messages
 
+SiweMessage的nonce说明(具体参考例子):
+
+```
+1. 从钱包预登录接口获取nonce
+2. nonce = nonce + '|' + 钱包类型字符串 // 比如okx钱包, nonce|okx
+3. 使用 活动id 作为 key, 调用aesEncrypt 加密步骤2的字符串
+4. 将hex string 转换成base58, 传给SiweMessage
+```
+
 
 
 #### Response