SOURCE

<div class="jumbotron">
    <h1>this is title</h1>
    <div class="search">
      <form action="">
      <div class="input-group">
        <input type="text" class="form-control" placeholder="this is you modules" aria-describedby="search-bn">
        <span class="input-group-addon" id="search-bn">搜索</span>
      </div>
        </form>
    </div>
</div>

.jumbotron>h1{
  text-align:center;
}
.input-group{
  width: 80%;
  margin: 0 auto;
  text-align:center;
  
}