固定顶部div fixed显示出absolute的感觉

<div class="container" style="position: relative">
  <div class="banner clear" style="position: absolute;left: 0px;top: 0;z-index: 1000">
      <div class="bannerL">
          <img src="image/logo.png">
          <span>彼邻同行</span>
      </div>
      <div class="bannerR">
          <a src="#">彼邻</a>
          <a src="#">拼车点</a>
          <a src="#">关于</a>
          <a src="#">投资我们</a>
      </div>
  </div>
</div>

css
.container {
    width: 100%;
    height: 120px;
    line-height: 120px;
    position: relative;
}
.banner{
    width: 100%;
    background: rgba(0, 0, 0, 0.28);
}
.banner>.bannerL{
    float: left;
    width: 30%;
}
.banner>.bannerL img{
    width: 20%;
}
.banner>.bannerL>span {
    font-size: 30px;
    color: #fefffe;
    margin-left: 2%;
    vertical-align: middle
}

.banner>.bannerR {
    float: right;
    width: 50%;
}

.banner>.bannerR>a {
    width: 24%;
    font-size: 18px;
    color: #fefffe;
    display: inline-block;
    line-height: 65px;
    text-align: center
}

js代码
window.onscroll = function(){
    $(".banner").css("top",$(document).scrollTop())
}

另一种方法

<div class="container" style="position: fixed;overflow: visible;width: 100%;z-index: 1000;">
  <div class="banner clear" id="banner" style="position: absolute;left: 0px;top: 0;min-width: 1000px;z-index: 1000;">
      <div class="bannerL">
          <img src="image/logo.png">
          <span>彼邻同行</span>
      </div>
      <div class="bannerR">
          <a src="#">彼邻</a>
          <a src="#">拼车点</a>
          <a src="#">关于</a>
          <a src="#">投资我们</a>
      </div>
  </div>
</div>