el-upload组件多个文件上传都是多次请求上传接口，没有在文档中找到能够通过一次请求把所有文件上传的设置。最后只能通过用组件的部分功能，抛弃组件上传功能，通过axios自己将所有文件一次上传。

<el-dialog :title="upload.title" :visible.sync="upload.open" width="400px" append-to-body>
  <el-upload 
    ref="upload" 
    :limit="10" 
    accept=".txt" 
    name="files" 
    :multiple="true" //可多选
    :action="upload.url" //必填随便填
    :headers="upload.headers"
    :disabled="upload.isUploading" 
    :on-change="handleFileChange"
    :before-remove="handleFileRemove" 
    :auto-upload="false"
    :file-list="upload.fileList" 
    drag
    >
    <i class="el-icon-upload"></i>
    <div class="el-upload__text">
      将文件拖到此处，或
      <em>点击上传</em>
    </div>
    <div class="el-upload__tip" style="color:red" slot="tip">提示：仅允许导入“txt”格式文件！</div>
  </el-upload>
  <div slot="footer" class="dialog-footer">
    <el-button type="primary" @click="submitFileForm">确 定</el-button>
    <el-button @click="upload.open = false">取 消</el-button>
  </div>
</el-dialog>

data() {
    return {
      upload: {
        // 是否显示弹出层（用户导入）
        open: false,
        // 弹出层标题（用户导入）
        title: '',
        // 是否禁用上传
        isUploading: false,
        // 是否更新已经存在的用户数据
        updateSupport: 0,
        // 设置上传的请求头部
        headers: { Authorization: getToken() },
        // 上传的地址
        url: baseURL + 'codefileupload/upload',
        fileList: [],
        fileName: []
      }
    };
  },
  
  methods:{
    // 上传发生变化钩子
    handleFileChange(file, fileList) {
      this.upload.fileList = fileList;
    },
    // 删除之前钩子
    handleFileRemove(file, fileList) {
      this.upload.fileList = fileList;
    },
    // 提交上传文件
    submitFileForm() {
      <!-- 创建新的数据对象 -->
      let formData = new FormData();
      <!-- 将上传的文件放到数据对象中 -->
      this.upload.fileList.forEach(file => {
        formData.append('files', file.raw);
        this.upload.fileName.push(file.name);
      });
      <!-- 文件名 -->
      formData.append('fileName', this.upload.fileName);
      <!-- 自定义上传 -->
      axios
        .post(this.upload.url, formData, { headers: { 'Content-Type': 'multipart/form-data', Authorization: getToken() } })
        .then(response => {
          if(response.code == 200){
            this.upload.open = false;
            this.upload.isUploading = false;
            this.$refs.upload.clearFiles();
            this.msgSuccess('上传成功！');
          }else{
            this.$message.error(response.msg);
          }
        })
        .catch(error => {
          this.$message.error('上传失败！');
        });
    }
  }