Hi
everthing in your code is correct just USE
IF conditional loop and modify condition as below
if (webBrowser1.ReadyState == WebBrowserReadyState.Complete)
{
Console.WriteLine("miao2");
Application.DoEvents();
}
else
{
Console.WriteLine("miao3");
HtmlElement Sumiaobut = this.webBrowser1.Document.GetElementById(submitFormBtnA);
Sumiaobut.InvokeMember("Click");
}