execCommand 文档
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>富文本上传图片</title>
<style>
#editor{
border: 1px solid #ccc;
width: 400px;
height: 200px;
margin-bottom: 30px;
}
#editor img{
/* 需要图片换行的话，可以设置display:block; */
display: block;
max-width: 100px;
}
</style>
</head>
<body>
<div id="editor" contenteditable="true">
123456123456
</div>
<input type="file" name="file" id="uploadFile" onchange="uploadFile(event)"/>
</body>
<script type="text/javascript" language="javascript">
var editer = document.getElementById('editer');
function uploadFile(e){
let file = e.target.files[0]; //需要上传到后台的图片
//上传后台，此处省略。。。。。。。。。。。
let filePath = 'http://qiniu.jnwtv.com/LC20180417174434604455636.jpg';
//filePath为后台返回的图片地址
editer.focus();
document.execCommand('InsertImage', false, filePath);
}
</script>
</html>