diff --git a/src/Gateways/UcloudGateway.php b/src/Gateways/UcloudGateway.php
index 1eee58a..fddfd3c 100644
--- a/src/Gateways/UcloudGateway.php
+++ b/src/Gateways/UcloudGateway.php
@@ -68,7 +68,7 @@ protected function buildParams(PhoneNumberInterface $to, MessageInterface $messa
         $data = $message->getData($this);
         $params = [
             'Action' => self::ENDPOINT_Action,
-            'SigContent' => $config->get('sig_content'),
+            'SigContent' => !empty($data['sig_content']) ? $data['sig_content'] : $config->get('sig_content', ''),
             'TemplateId' => $message->getTemplate($this),
             'PublicKey' => $config->get('public_key'),
         ];
diff --git a/tests/Gateways/UcloudGatewayTest.php b/tests/Gateways/UcloudGatewayTest.php
index 999dfa9..248c509 100644
--- a/tests/Gateways/UcloudGatewayTest.php
+++ b/tests/Gateways/UcloudGatewayTest.php
@@ -69,4 +69,46 @@ public function testSend()
 
         $gateway->send(new PhoneNumber(18888888888), $message, $config);
     }
+    
+    public function testSignContent()
+    {
+        $defaultSigContent = 'default_sig_content';
+        
+        $dataSigContent = 'data_sig_content';
+        
+        $config = [
+            'private_key' => '', //私钥
+            'public_key' => '', //公钥
+            'sig_content' => $defaultSigContent, //签名
+            'project_id' => '',
+        ];
+        $easySms = new EasySms($config);
+        
+        $phoneNumber = new PhoneNumber('18888888888');
+        $gateway = $easySms->gateway('ucloud');
+        
+        $reflectionMethod = new \ReflectionMethod(get_class($gateway), 'buildParams');
+        $reflectionMethod->setAccessible(true);
+        //验证指定签名
+        $message = new Message([
+            'template' => '',
+            'data' => [
+                'code' => '', // 如果是多个参数可以用数组
+                'mobiles' => '', //同时发送多个手机也可以用数组来,[1111111,11111]
+                'sig_content'=>$dataSigContent
+            ],
+        ]);
+        $result = $reflectionMethod->invokeArgs($gateway, [$phoneNumber, $message, $easySms->getConfig()]);
+        $this->assertSame($dataSigContent, $result['SigContent']);
+        //验证配置默认签名
+        $message = new Message([
+            'template' => '',
+            'data' => [
+                'code' => '', // 如果是多个参数可以用数组
+                'mobiles' => '', //同时发送多个手机也可以用数组来,[1111111,11111]
+            ],
+        ]);
+        $result = $reflectionMethod->invokeArgs($gateway, [$phoneNumber, $message, $easySms->getConfig()]);
+        $this->assertSame($defaultSigContent, $result['SigContent']);
+    }
 }