页面部分

<el-upload  
    class="upload-demo"
    action="https://jsonplaceholder.typicode.com/posts/"              
    :on-success="handleChange"             
    accept=".txt"            
    :file-list="fileList">//accept=".txt" 只允许上传txt文件 :on-success上传成功再读取数据
    <el-button size="small" type="primary">上传</el-button>             
</el-upload>          

js部分

handleChange(response,file, fileList) {
     let reader=new FileReader();
     reader.readAsText(file.raw,'UTF-8')//读取，转换字符编码
     reader.onload=function(e){
         let val=e.target.result;//获取数据
         let rtulist=val.split("\r\n")
         console.log('rtulist:>> ', rtulist);
      }
 }