<div>    
      <form id="coa_form_@{{d.id}}" action="{{route("admin.company.upload_coa")}}" accept-charset="UTF-8"  method="post">
       @csrf
       <input type="hidden" name="company_id" value="@{{d.id}}">
       <input type="hidden" name="cas" value="{{$inquiries->prod->cas}}">
       <input type="file" id="upload@{{d.id}}" name="coa_file" rel="@{{d.id}}" value="">
       </form>
    </div>

    <script>    
            layui.use(['layer','table','form','element','upload'],function () {
                var $ = layui.jquery;
                var layer = layui.layer;
                var form = layui.form;
                var table = layui.table;
                var element = layui.element;
                var upload = layui.upload;
                if (layEvent === 'upload'){
                  var rel = $(this).attr('rel');
                  var file_dom = 'upload'+rel;
                  var coa_form = 'coa_form_'+rel;
                  if($("#"+file_dom).val() == ''){
                     layer.msg('请上传附件', {icon: 5,time:1500});
                     return;
                  }
                  var formData = new FormData($("#"+coa_form)[0]);
                  $.ajax({
                     url: $("#"+coa_form).attr('action'),
                     data: formData,
                     type: 'post',
                     cache: false,
                     contentType: false,
                     processData: false,
                     success: function (data) {
                       layer.msg(data.msg, {
                            icon: 1,
                            time: 1500 //1秒关闭（如果不配置，默认是3秒）
                            }, function(){
                              //window.location.reload();
                              table.reload('dataTable', {
                                 where: {
                                     company_info: $("#search_company_info").val(),
                                 }
                                 ,page:obj.curr
                                 });
                                  });
                     },
                     error: function () {
                        layer.msg('系统异常，请联系客服人员！', {icon: 5,time:1500});
                        return;
                        }
                     });
                  }
                });
    </script>

服务端处理

    public function upload_coa(Request $request){    
        $data['cas'] = $request->get('cas');
        $data['company_id'] = $request->get('company_id');
        $manage_id = isset(auth('web')->user()->id) ?auth('web')->user()->id : 0;
        $manage_name = isset(auth('web')->user()->name) ?auth('web')->user()->name : '';
        //不为空
        if($request->hasFile('coa_file')){
           $file = $request->file('coa_file');
           $fileExtension = $file->getClientOriginalExtension();
           if(! in_array($fileExtension, ['jpg', 'png','jpeg','gif','pdf','doc','docx','csv','xls','xlsx'])) {
               return false;
           }
           $data['file_original_name'] = $file->getClientOriginalName();
           $data['file_size'] = $file->getClientSize();
           $data['file_suffix'] = $fileExtension;
           //临时绝对路径
           $filePath = $file->getRealPath();
           $filename = date('Ymdhis').mt_rand(1000,9999).'.'.$fileExtension;
           Storage::disk('coa')->put($filename, file_get_contents($filePath));
           $data['file_name'] = $filename;
           $data['file_path'] = '/storage/coa/'.$filename;
           $data['url'] = config('app.url').$data['file_path'];
           $data['status'] = 1;
           $data['manage_id'] = $manage_id;
           $data['manage_name'] = $manage_name;
        }
        if(Coa::create($data)){
           return Y::success('上传coa成功！');
        }else{
           return Y::error('上传coa失败！');
       }
    }