.search_content_list {width:374px;display: none;}
.search_content_list ul{border:#ddd 1px solid;border-top:none;padding:5px}
.search_content_list ul li{height:30px;line-height: 30px;clear:both;}
.search_content_list ul li p{float:left;margin:0;padding:0;}
.search_content_list ul li a{float:right;text-decoration:underline;}
<div class="formControls" style="width:376px;position: absolute;left:calc(50% - 188px);top:calc(20% - 16px);">
<span class="form-group">
<input class="input-text size-L" type="text" name="keyword" id="keyword" placeholder="请输入单位关键词" style="width: 374px;">
</span>
<div class="search_content_list">
<ul id="search_ent_list"></ul>
</div>
</div>
重点在于下面的propertychange,这个方法是输入一个字就被监听一次
$(document).ready(function(){
$("#keyword").bind('input propertychange', function () {
$('.search_content_list').show();
var keyword = $(this).val();
$.ajax({
type: "POST",
url: '/company/ajax_search_content.php',
data: {keyword:keyword},
success: function(data){
if(data.state == 'success'){
$('#search_ent_list').html('');
var list = data.data;
var count = list.length;
var html = '';
for(var i=0;i<count;i++){
html += '<li><p>'+list[i].ent_name+'</p><a href="/company/company_info.php?id='+list[i].id+'">查看</a></li>';
}
$('#search_ent_list').append(html);
}
}
});
});
});