代码：
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <style> .dot{ margin-top: 300px; position: absolute; width: 1px; height: 1px; background: #000000; } #ball{ width: 10px; height: 10px; background: red; border: 1px solid red; position: absolute; border-radius: 10px; } </style> </head> <body> <div > </div> <div ></div> <script type="text/javascript"> var dom=document.getElementById("draw_bo"); var ball=document.getElementById("ball"); var x=0,y=300; ball.style.left=x+"px";//小球初始坐标x ball.style.top=y+"px";//小球初始坐标y for(var angle=0;angle<600;angle+=0.01){//画正弦线 var childDot=document.createElement('div'); childDot.className='dot'; childDot.style.top=300*(Math.sin(angle*Math.PI/300))+"px"; childDot.style.left=angle+"px"; dom.appendChild(childDot); } var time=setInterval(function () { x=x+5;//小球运动速度 y=Math.floor(Math.sin(x/600*2*Math.PI)*300)+300;//小球运动的高度 if(x>600) x=0; ball.style.left=x+"px"; ball.style.top=y+"px"; },100); </script> </body> </html>