Upload pictures on php curl

upload pictures using curl. Keep reporting timeout errors.

Operation timed out after 30000 milliseconds with 0 bytes received

my curl function is as follows:

function myCurl($data, $file = null)
{
    if (!empty($file)) {
       $file_obj = curl_file_create(realpath($file), "image/png", "550759_yuan521.png");
       $data["imgs"] = $file_obj;
       $data = http_build_query($data);
    }
    $opt = [
        CURLOPT_URL => "http://localhost/test/2.php", // 
        CURLOPT_POST => true,
        CURLOPT_TIMEOUT => 30,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_HEADER => 0,
        CURLOPT_POSTFIELDS => $data,
        CURLOPT_SSL_VERIFYPEER => 0
    ];
    $ch = curl_init();
    curl_setopt_array($ch, $opt);
    $output = curl_exec($ch);
    $error = curl_error($ch);
    curl_close($ch);
    if ($error) {
        return $error;
    } else {
        return $output;
    }
}

< hr >

2.php wrote only one line of code

print_r($_FILES);

< hr >

php version is: php-7.0.12-nts

the size of the test image is only 100k

< hr >

my curl function is as follows:

Please don"t hesitate to give us your advice and thank you!