diff --git a/backend/services/identity-service/src/shared/utils/random-identity.util.ts b/backend/services/identity-service/src/shared/utils/random-identity.util.ts
index 1a37dff4..3c2ba5d6 100644
--- a/backend/services/identity-service/src/shared/utils/random-identity.util.ts
+++ b/backend/services/identity-service/src/shared/utils/random-identity.util.ts
@@ -3,8 +3,14 @@
  */
 
 // 生成用户名: 榴莲女皇x号
+// accountSequence 格式: D + YYMMDD + 5位序号 (如 D24121400001)
+// 提取后5位序号，去掉前导零
 export function generateUsername(accountSequence: string): string {
-  return `榴莲女皇${accountSequence}号`;
+  // 提取后5位序号
+  const serialPart = accountSequence.slice(-5);
+  // 去掉前导零，转为数字再转回字符串
+  const serialNumber = parseInt(serialPart, 10).toString();
+  return `榴莲女皇${serialNumber}号`;
 }
 
 // 预定义的柔和配色方案