diff --git a/jpress-web/src/main/java/io/jpress/web/commons/express/impl/Kuaidi100ExpressQuerier.java b/jpress-web/src/main/java/io/jpress/web/commons/express/impl/Kuaidi100ExpressQuerier.java
index f899da8bb2c9fadf658ff6ff3e2306fcb4222193..68718a66be065509011735dbecca7bca493d3b1a 100644
--- a/jpress-web/src/main/java/io/jpress/web/commons/express/impl/Kuaidi100ExpressQuerier.java
+++ b/jpress-web/src/main/java/io/jpress/web/commons/express/impl/Kuaidi100ExpressQuerier.java
@@ -50,7 +50,7 @@ public class Kuaidi100ExpressQuerier implements ExpressQuerier {
         String appSecret = JPressOptions.get("express_api_appsecret");
 
         String param = "{\"com\":\"" + company.getCode() + "\",\"num\":\"" + num + "\"}";
-        String sign = HashKit.md5(param + appSecret + appId);
+        String sign = HashKit.md5(param + appSecret + appId).toUpperCase();
         HashMap params = new HashMap();
         params.put("param", param);
         params.put("sign", sign);