// Form Submit Handler
$( '#form-parameters' ).submit(function (event) {

        event.preventDefault();

        var formData = $(this).serialize();
        // Post serialized form data
        postAssemblyParameters(formData);
});

// Post Form Data to controller test
function postAssemblyParameters(formData){
        $.ajax({
                url: http://localhost/api/test/1,type: 'POST',data: formData,dataType: 'application/x-www-form-urlencoded',success: function(x3d) {
                },error: function(xhr) {

                }
        });
}

服务器端使用Web API自主主机：

public void Post([FromUri] int id,[FromBody] NameValueCollection formData)
{
        Console.WriteLine(id); // OK

        // Collection is NULL
        foreach (var key in formData.AllKeys)
        {
                foreach (var val in formData.GetValues(key))
                {
                        Console.WriteLine(key + ": " + val);
                }
        }
}

非常感谢.