//1.获取文本
let topDiff =-1; let content="";
var filename= document.getElementsByClassName('doc-title')[0].innerText;

const target = document.querySelectorAll(".reader-word-layer"); 
target.forEach(x=>{
		if (x.style.top !== topDiff){
		content +="\n"
		topDiff = x.style.top;
		}

		content += x.innerText;
});
//2.创建下载链接，下载到本地
var element = document.createElement('a');
element.setAttribute( 'href','data:text/plain;charset-utf-8,'+encodeURIComponent(content));
element.setAttribute( 'download', filename+".doc");

element.style.display=".reader-word-layer"; 
document.body.appendChild(element);
element.click();
document.body.removeChild(element);

不做解释了，都是很简单的toy代码