<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> <style> .box { 50px;; margin: 100px auto; } .box li { float: left; 20px; height: 20px; background-color: pink; margin: 15px; background: url(OIP.jpg) no-repeat; } </style> </head> <body> <div class="box"> <ul> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> <li></li> </ul> <script> //1.获取元素 var lis = document.querySelectorAll('li'); for(var i = 0 ; i<lis.length ;i++) { //让索引号乘以44 就是每个li的背景坐标 //index就是我们的y坐标 var index = i*44; lis[i].style.backgroundPosition = '0 -'+index+'px'; console.log(lis[i].style.backgroundPosition); } </script> </div> </body> </html>