更全面的平滑滚动方法列表见我的回答here。
要在准确的时间内滚动到某个位置，可以使用window.requestAnimationFrame，每次计算适当的当前位置。在不支持requestAnimationFrame 时，可以使用setTimeout 达到类似的效果。
/*
@param pos: the y-position to scroll to (in pixels)
@param time: the exact amount of time the scrolling will take (in milliseconds)
*/
function scrollToSmoothly(pos, time) {
var currentPos = window.pageYOffset;
var start = null;
if(time == null) time = 500;
pos = +pos, time = +time;
window.requestAnimationFrame(function step(currentTime) {
start = !start ? currentTime : start;
var progress = currentTime - start;
if (currentPos < pos) {
window.scrollTo(0, ((pos - currentPos) * progress / time) + currentPos);
} else {
window.scrollTo(0, currentPos - ((currentPos - pos) * progress / time));
}
if (progress < time) {
window.requestAnimationFrame(step);
} else {
window.scrollTo(0, pos);
}
});
}
演示：
function scrollToSmoothly(pos, time) {
var currentPos = window.pageYOffset;
var start = null;
if(time == null) time = 500;
pos = +pos, time = +time;
window.requestAnimationFrame(function step(currentTime) {
start = !start ? currentTime : start;
var progress = currentTime - start;
if (currentPos < pos) {
window.scrollTo(0, ((pos - currentPos) * progress / time) + currentPos);
} else {
window.scrollTo(0, currentPos - ((currentPos - pos) * progress / time));
}
if (progress < time) {
window.requestAnimationFrame(step);
} else {
window.scrollTo(0, pos);
}
});
}
document.getElementById("toElement").addEventListener('click', function(e) {
var elem = document.querySelector("div");
scrollToSmoothly(elem.offsetTop);
});
document.getElementById("toTop").addEventListener('click', function(e){
scrollToSmoothly(0, 700);
});
<button id="toElement">Scroll To Element</button>
<div style="margin: 1000px 0px; text-align: center;">Div element
<button id="toTop">Scroll back to top</button>
</div>
对于更复杂的情况，可以使用SmoothScroll.js library，它可以处理垂直和水平平滑滚动、在其他容器元素内滚动、不同的缓动行为、从当前位置相对滚动等等。
document.getElementById("toElement").addEventListener('click', function(e) {
smoothScroll({toElement: document.querySelector('div'), duration: 500});
});
document.getElementById("toTop").addEventListener('click', function(e){
smoothScroll({yPos: 0, duration: 700});
});
<script src="https://cdn.jsdelivr.net/gh/LieutenantPeacock/SmoothScroll@1.2.0/src/smoothscroll.min.js" integrity="sha384-UdJHYJK9eDBy7vML0TvJGlCpvrJhCuOPGTc7tHbA+jHEgCgjWpPbmMvmd/2bzdXU" crossorigin="anonymous"></script>
<button id="toElement">Scroll To Element</button>
<div style="margin: 1000px 0px; text-align: center;">Div element
<button id="toTop">Scroll back to top</button>
</div>
或者，您可以将选项对象传递给 window.scroll 滚动到特定的 x 和 y 位置，window.scrollBy 从当前位置滚动一定量：
// Scroll to specific values
// scrollTo is the same
window.scroll({
top: 2500,
left: 0,
behavior: 'smooth'
});
// Scroll certain amounts from current position
window.scrollBy({
top: 100, // could be negative value
left: 0,
behavior: 'smooth'
});
演示：
<button onClick="scrollToDiv()">Scroll To Element</button>
<div style="margin: 500px 0px;">Div</div>
<script>
function scrollToDiv(){
var elem = document.querySelector("div");
window.scroll({
top: elem.offsetTop,
left: 0,
behavior: 'smooth'
});
}
</script>
现代浏览器支持scroll-behavior CSS property，可用于平滑滚动文档（无需JavaScript）。锚标签可以通过给锚标签一个href 或# 加上要滚动到的元素的id 来使用）。您还可以为div 等特定容器设置scroll-behavior 属性，以使其内容平滑滚动。
演示：
html, body{
scroll-behavior: smooth;
}
<a href="#elem">Scroll To Element</a>
<div id="elem" style="margin: 500px 0px;">Div</div>