window.onunload = function() {} setFontSize() window.onresize = function() { setFontSize() } function setFontSize() { let designSize = 1920; // 设计图尺寸 let html = document.documentElement; let wW = html.clientWidth;// 窗口宽度 let rem = wW * 100 / designSize; document.documentElement.style.fontSize = rem + 'px'; }