<div class="rotary">
    <div class="rotaryArrow" id="rotaryArrow"></div>
    <div class="list">
        <ul id="li">
        </ul>
    </div>
 <script type="text/javascript">
    $.ajax({
        type:'POST',
        url:'test1.php',
        data:['li'],
        dataType: 'json',
        cache:false,
        error: function(){ 
            alert('出错了！'); 
            return false; 
        },
success: function(json){
    var list = '';
    for(var o in json){
        list += json[o];
    }

    $("#li").html(list);
}
    });

<?php
$servername = "localhost";
$username = "root";
$password = "123";
$dbname = "list";
$conn = new mysqli($servername, $username,$password,$dbname);
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 
$sql = "SELECT num FROM tele";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
    $li='';
    while($row = $result->fetch_assoc()) {
        $li .= '<li>'. $row["num"].'</li>';
    }
} else {
    echo "0 results";
}

$conn->close(); 
echo json_encode($li); 
?>