htmlのpost requestにおけるaタグの2つの使い方を説明します。

<a href="https://www.jb51.net/" class="a_post">Initiating a POST request</a>

$(".a_post").on("click",function(event){
    event.preventDefault();// disable the method that comes with a, i.e. it can't be adjusted to the URL in the href (https://www.cnblogs.com/)
    $.ajax({
           type: "POST",
           url: "url address",
           contentType:"application/json",
           data: JSON.stringify({param1:param1,param2:param2}),//parameter list
           dataType:"json",
           success: function(result){
              // action after the request is correct
           },
           error: function(result){
              // action after the request fails
           }
    });
});

<form id="_form" method="post" action="target">
  <input type="hidden" name="name" value="value" /> 
  <a onclick="document.getElementById('_form').submit();">Click submit</a>
</form>