diff --git a/CHANGELOG.md b/CHANGELOG.md
index 55b6a25..6ec2cf6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+## v3.0.19
+
+### fixed
+
+- fix: 支付宝 system.oauth.token 请求参数错误 (#528)
+
 ## v3.0.18
 
 ### added
diff --git a/src/Plugin/Alipay/Tools/SystemOauthTokenPlugin.php b/src/Plugin/Alipay/Tools/SystemOauthTokenPlugin.php
index ce47a33..336d9e9 100644
--- a/src/Plugin/Alipay/Tools/SystemOauthTokenPlugin.php
+++ b/src/Plugin/Alipay/Tools/SystemOauthTokenPlugin.php
@@ -5,9 +5,15 @@ declare(strict_types=1);
 namespace Yansongda\Pay\Plugin\Alipay\Tools;
 
 use Yansongda\Pay\Plugin\Alipay\GeneralPlugin;
+use Yansongda\Pay\Rocket;
 
 class SystemOauthTokenPlugin extends GeneralPlugin
 {
+    protected function doSomethingBefore(Rocket $rocket): void
+    {
+        $rocket->mergePayload($rocket->getParams());
+    }
+
     protected function getMethod(): string
     {
         return 'alipay.system.oauth.token';
diff --git a/tests/Plugin/Alipay/Tools/SystemOauthTokenPluginTest.php b/tests/Plugin/Alipay/Tools/SystemOauthTokenPluginTest.php
new file mode 100644
index 0000000..5533c4d
--- /dev/null
+++ b/tests/Plugin/Alipay/Tools/SystemOauthTokenPluginTest.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace Yansongda\Pay\Tests\Plugin\Alipay\Tools;
+
+use Yansongda\Pay\Parser\ResponseParser;
+use Yansongda\Pay\Plugin\Alipay\Tools\SystemOauthTokenPlugin;
+use Yansongda\Pay\Rocket;
+use Yansongda\Pay\Tests\TestCase;
+
+class SystemOauthTokenPluginTest extends TestCase
+{
+    public function testNormal()
+    {
+        $rocket = new Rocket();
+        $rocket->setParams(['name' => 'yansongda', 'age' => 28]);
+
+        $plugin = new SystemOauthTokenPlugin();
+
+        $result = $plugin->assembly($rocket, function ($rocket) { return $rocket; });
+
+        self::assertEquals('yansongda', $result->getPayload()->get('name'));
+        self::assertEquals(28, $result->getPayload()->get('age'));
+    }
+}