composer require phpoffice/phpexcel

不管它的警告，都能用的。

use PHPExcel;
use PHPExcel_IOFactory;

public static function exportExcel($expTitle, $expCellName, $expTableData, $topData) {
    $xlsTitle = iconv('utf-8', 'gb2312', $expTitle);//文件名称
    $fileName = $xlsTitle;//or $xlsTitle 文件名称可根据自己情况设定
    $cellNum = count($expCellName);
    $dataNum = count($expTableData);
    $topNum  = count($topData);

    $objPHPExcel = new \PHPExcel();
    $cellName = array('A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'AA', 'AB', 'AC', 'AD', 'AE', 'AF', 'AG', 'AH', 'AI', 'AJ', 'AK', 'AL', 'AM', 'AN', 'AO', 'AP', 'AQ', 'AR', 'AS', 'AT', 'AU', 'AV', 'AW', 'AX', 'AY', 'AZ');

    $objPHPExcel->getActiveSheet(0)->mergeCells('A1:' . $cellName[$cellNum - 1] . '1');//合并单元格
    $objPHPExcel->setActiveSheetIndex(0)->setCellValue('A1', $expTitle);

    for ($i = 0; $i < count($topData); $i++) {
        for ($j = 0; $j < count($topData[$i]); $j++) {
            $objPHPExcel->setActiveSheetIndex(0)->setCellValue($cellName[$j] . ($i + 2), $topData[$i][$j]);
        }
    }

    for ($i = 0; $i < $cellNum; $i++) {
        $objPHPExcel->setActiveSheetIndex(0)->setCellValue($cellName[$i] . ($topNum + 2), $expCellName[$i][1]);
    }
    // Miscellaneous glyphs, UTF-8
    for ($i = 0; $i < $dataNum; $i++) {
        for ($j = 0; $j < $cellNum; $j++) {
            if ($expCellName[$j][0] == 'account_type') {
                if ($expTableData[$i][$expCellName[$j][0]] == 0) {
                    $objPHPExcel->getActiveSheet(0)->setCellValue($cellName[$j] . ($i + $topNum + 3), '餐饮');
                } else {
                    $objPHPExcel->getActiveSheet(0)->setCellValue($cellName[$j] . ($i + $topNum + 3), '果蔬');
                }
            } else {
                $objPHPExcel->getActiveSheet(0)->setCellValue($cellName[$j] . ($i + $topNum + 3), $expTableData[$i][$expCellName[$j][0]]);
            }
        }
    }

    header('pragma:public');
    header('Content-type:application/vnd.ms-excel;charset=utf-8;name="' . $xlsTitle . '.xls"');
    header("Content-Disposition:attachment;filename=$fileName.xls");//attachment新窗口打印inline本窗口打印
    $objWriter = \PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
    $objWriter->save('php://output');
    exit;
}

public function export_excel() {
    $where = new Where();
    $result = $this->model->where($where)->order('id desc')->select();
    // 导出到excel
    foreach ($result as $k=>&$v) {
        $v['add_time'] = date('Y-m-d H:i',$v['add_time']);
        switch ($v['status']) {
            case 0:
                $v['status'] = '未处理';
                break;
            case 1:
                $v['status'] = '已同意申请';
                break;
            case 2:
                $v['status'] = '已拒绝申请';
                break;
        }
    }

    $xlsCell  = array(
        array('id','ID'),
        array('name','姓名'),
        array('telphone','手机号'),
        array('add_time','领取时间'),
        array('status','状态')
    );

    $xlsName = date('Y-m-d').'申请加入名单';
    Func::exportExcel($xlsName, $xlsCell, $result);
}

tips:tp5.1已经废弃了Loader引入。