diff --git a/src/HttpRequest.php b/src/HttpRequest.php
index f88b134..106d190 100644
--- a/src/HttpRequest.php
+++ b/src/HttpRequest.php
@@ -5,6 +5,7 @@
 use Yurun\Util\YurunHttp\Attributes;
 use Yurun\Util\YurunHttp\Http\Psr7\Consts\MediaType;
 use Yurun\Util\YurunHttp\Http\Psr7\UploadedFile;
+use Yurun\Util\YurunHttp\Http\Psr7\Uri;
 use Yurun\Util\YurunHttp\Http\Request;
 
 class HttpRequest
@@ -448,6 +449,10 @@ public function rawHeaders($headers)
         $thisHeaders = &$this->headers;
         foreach ($headers as $header)
         {
+            if (!str_contains($header, ':'))
+            {
+                continue;
+            }
             $list = explode(':', $header, 2);
             $thisHeaders[trim($list[0])] = trim($list[1]);
         }
@@ -464,6 +469,10 @@ public function rawHeaders($headers)
      */
     public function rawHeader($header)
     {
+        if (!str_contains($header, ':'))
+        {
+            return $this;
+        }
         $list = explode(':', $header, 2);
         $this->headers[trim($list[0])] = trim($list[1]);
 
@@ -1014,15 +1023,18 @@ public function get($url = null, $requestBody = null)
     {
         if (!empty($requestBody))
         {
-            if (strpos($url, '?'))
+            if (null === $url)
             {
-                $url .= '&';
+                $url = $this->url;
             }
-            else
+            $uri = new Uri($url);
+            $query = $uri->getQuery();
+            if ('' !== $query)
             {
-                $url .= '?';
+                $query .= '&';
             }
-            $url .= http_build_query($requestBody, '', '&');
+            $query .= http_build_query($requestBody, '', '&');
+            $url = (string) $uri->withQuery($query);
         }
 
         return $this->send($url, [], 'GET');
diff --git a/src/YurunHttp/Handler/Curl.php b/src/YurunHttp/Handler/Curl.php
index 822ac48..9d2c40e 100644
--- a/src/YurunHttp/Handler/Curl.php
+++ b/src/YurunHttp/Handler/Curl.php
@@ -462,7 +462,7 @@ private function parseHeaderOneRequest($headers)
         for ($i = 1; $i < $count; ++$i)
         {
             $line = trim($headers[$i]);
-            if (empty($line) || false == strstr($line, ':'))
+            if (empty($line) || false === strstr($line, ':'))
             {
                 continue;
             }
@@ -570,6 +570,10 @@ private function parseOptions(&$request, &$options, &$headers = null, &$saveFile
                 $saveFilePath .= basename($request->getUri()->__toString());
             }
             $saveFileFp = fopen($saveFilePath, $request->getAttribute(Attributes::SAVE_FILE_MODE, 'w+'));
+            if (false === $saveFileFp)
+            {
+                throw new \RuntimeException(sprintf('fopen save file failed: %s', $saveFilePath));
+            }
             $options[\CURLOPT_HEADER] = false;
             $options[\CURLOPT_RETURNTRANSFER] = false;
             $options[\CURLOPT_FILE] = $saveFileFp;
@@ -670,7 +674,7 @@ private function parseNetwork(&$request, &$options)
     {
         // 用户名密码处理
         $username = $request->getAttribute(Attributes::USERNAME);
-        if (null != $username)
+        if (null !== $username)
         {
             $userPwd = $username . ':' . $request->getAttribute(Attributes::PASSWORD, '');
         }
@@ -762,7 +766,10 @@ public function coBatch($requests, $timeout = null)
                     {
                         break;
                     }
-                    usleep(5000); // 每次延时 5 毫秒
+                    if (-1 === curl_multi_select($mh, 0.5))
+                    {
+                        usleep(250);
+                    }
                 }
                 else
                 {
diff --git a/src/YurunHttp/Handler/Swoole.php b/src/YurunHttp/Handler/Swoole.php
index 61a0db4..ec68b01 100644
--- a/src/YurunHttp/Handler/Swoole.php
+++ b/src/YurunHttp/Handler/Swoole.php
@@ -810,7 +810,6 @@ public function coBatch($requests, $timeout = null)
             $request1 = $handler->sendDefer($request1);
         }
         unset($request1);
-        $beginTime = microtime(true);
         $recvTimeout = null;
         foreach ($requests as $i => $request2)
         {
diff --git a/src/YurunHttp/Handler/Swoole/SwooleHttp2ConnectionPool.php b/src/YurunHttp/Handler/Swoole/SwooleHttp2ConnectionPool.php
index c2ce25f..17c94f2 100644
--- a/src/YurunHttp/Handler/Swoole/SwooleHttp2ConnectionPool.php
+++ b/src/YurunHttp/Handler/Swoole/SwooleHttp2ConnectionPool.php
@@ -29,7 +29,9 @@ class SwooleHttp2ConnectionPool extends BaseConnectionPool
     public function __construct($config)
     {
         parent::__construct($config);
-        $this->channel = new Channel(1024);
+        $maxConnections = $config->getMaxConnections();
+        $capacity = $maxConnections > 0 ? $maxConnections : 1024;
+        $this->channel = new Channel($capacity);
     }
 
     /**
@@ -41,7 +43,9 @@ public function close()
     {
         $connections = $this->connections;
         $this->connections = [];
-        $this->channel = new Channel(1024);
+        $maxConnections = $this->config->getMaxConnections();
+        $capacity = $maxConnections > 0 ? $maxConnections : 1024;
+        $this->channel = new Channel($capacity);
         foreach ($connections as $connection)
         {
             $connection->close();
diff --git a/src/YurunHttp/Handler/Swoole/SwooleHttpConnectionPool.php b/src/YurunHttp/Handler/Swoole/SwooleHttpConnectionPool.php
index ddc908d..581a525 100644
--- a/src/YurunHttp/Handler/Swoole/SwooleHttpConnectionPool.php
+++ b/src/YurunHttp/Handler/Swoole/SwooleHttpConnectionPool.php
@@ -29,7 +29,9 @@ class SwooleHttpConnectionPool extends BaseConnectionPool
     public function __construct($config)
     {
         parent::__construct($config);
-        $this->channel = new Channel(1024);
+        $maxConnections = $config->getMaxConnections();
+        $capacity = $maxConnections > 0 ? $maxConnections : 1024;
+        $this->channel = new Channel($capacity);
     }
 
     /**
@@ -41,7 +43,9 @@ public function close()
     {
         $connections = $this->connections;
         $this->connections = [];
-        $this->channel = new Channel(1024);
+        $maxConnections = $this->config->getMaxConnections();
+        $capacity = $maxConnections > 0 ? $maxConnections : 1024;
+        $this->channel = new Channel($capacity);
         foreach ($connections as $connection)
         {
             $connection->close();
diff --git a/tests/unit/HttpRequestTest/HttpRequestTest.php b/tests/unit/HttpRequestTest/HttpRequestTest.php
index dcb56e9..38d4bb6 100644
--- a/tests/unit/HttpRequestTest/HttpRequestTest.php
+++ b/tests/unit/HttpRequestTest/HttpRequestTest.php
@@ -825,4 +825,97 @@ public function testCookieJar(): void
             $this->assertEquals('3', isset($data['cookie']['c']) ? $data['cookie']['c'] : null);
         });
     }
+
+    /**
+     * rawHeader/rawHeaders 跳过不含冒号的行（避免未定义索引警告）.
+     *
+     * @return void
+     */
+    public function testRawHeaderWithoutColon(): void
+    {
+        $this->call(function () {
+            $http = new HttpRequest();
+            $http->rawHeader('X-NoColon')
+                 ->rawHeaders([
+                     'X-Valid: 1',
+                     'X-NoColon2',
+                 ]);
+            $this->assertArrayHasKey('X-Valid', $http->headers);
+            $this->assertEquals('1', $http->headers['X-Valid']);
+            $this->assertArrayNotHasKey('X-NoColon', $http->headers);
+            $this->assertArrayNotHasKey('X-NoColon2', $http->headers);
+        });
+    }
+
+    /**
+     * get() 在已有查询参数时正确拼接请求体.
+     *
+     * @return void
+     */
+    public function testGetWithExistingQueryAndBody(): void
+    {
+        $this->call(function () {
+            $http = new HttpRequest();
+            $time = time();
+            $response = $http->get($this->host . '?a=info', [
+                'time' => $time,
+            ]);
+            $this->assertResponse($response);
+            $data = $response->json(true);
+            $this->assertEquals('GET', isset($data['method']) ? $data['method'] : null);
+            $this->assertEquals($time, isset($data['get']['time']) ? $data['get']['time'] : null);
+        });
+    }
+
+    /**
+     * 保存文件 fopen 失败时抛出 RuntimeException.
+     *
+     * @return void
+     */
+    public function testSaveFileFopenFailureThrows(): void
+    {
+        $this->expectException(\RuntimeException::class);
+        $this->call(function () {
+            YurunHttp::setDefaultHandler(\Yurun\Util\YurunHttp\Handler\Curl::class);
+            set_error_handler(function () {
+                return true;
+            }, \E_WARNING);
+            try
+            {
+                $http = new HttpRequest();
+                $http->saveFile('/path/does/not/exist/yurunhttp_test_save.txt')
+                     ->get($this->host);
+            }
+            finally
+            {
+                restore_error_handler();
+            }
+        });
+    }
+
+    /**
+     * 连接池 Channel 容量等于最大连接数，未配置时为 1024.
+     *
+     * @return void
+     */
+    public function testConnectionPoolChannelCapacity(): void
+    {
+        if (!\extension_loaded('swoole'))
+        {
+            $this->markTestSkipped('Requires ext/swoole');
+        }
+        $config = new \Yurun\Util\YurunHttp\Pool\Config\PoolConfig($this->host, 5, 0.0);
+        $pool = new \Yurun\Util\YurunHttp\Handler\Swoole\SwooleHttpConnectionPool($config);
+        $ref = new \ReflectionProperty($pool, 'channel');
+        $ref->setAccessible(true);
+        $channel = $ref->getValue($pool);
+        $this->assertEquals(5, $channel->capacity);
+
+        $config2 = new \Yurun\Util\YurunHttp\Pool\Config\PoolConfig($this->host, 0, 0.0);
+        $pool2 = new \Yurun\Util\YurunHttp\Handler\Swoole\SwooleHttpConnectionPool($config2);
+        $ref2 = new \ReflectionProperty($pool2, 'channel');
+        $ref2->setAccessible(true);
+        $channel2 = $ref2->getValue($pool2);
+        $this->assertEquals(1024, $channel2->capacity);
+    }
 }