目前仅支持单个sheet


// 示例数据
const jsonData = [{
    name: '测试数据',
    phone: '123456',
    email: '123@456.com'
}]
// 列标题
let worksheet = 'sheet1'
let str = '<tr><td>姓名</td><td>电话</td><td>邮箱</td></tr>'
// 循环遍历,每行加入tr标签,每个单元格加td标签
for (let i = 0; i < jsonData.length; i++) {
    str += '<tr>'
    for (let item in jsonData[i]) {
        // 增加\t为了不让表格显示科学计数法或者其他格式
        str += `<td>${jsonData[i][item] + '\t'}</td>`
    }
    str += '</tr>'
}
// 下载的表格模板数据
let template =

    `<html xmlns:o="urn:schemas-microsoft-com:office:office" 
        xmlns:x="urn:schemas-microsoft-com:office:excel" 
        xmlns="http://www.w3.org/TR/REC-html40">
        <head>
            <!--[if gte mso 9]>
            <xml encoding="UTF-8">
            <x:ExcelWorkbook>
                <x:ExcelWorksheets>
                    <x:ExcelWorksheet>
                        <x:Name>${worksheet}</x:Name>
                        <x:WorksheetOptions>
                            <x:DisplayGridlines/>
                        </x:WorksheetOptions>
                    </x:ExcelWorksheet>
                    <x:ExcelWorksheet>
                        <x:Name>${worksheet}</x:Name>
                        <x:WorksheetOptions>
                            <x:DisplayGridlines/>
                        </x:WorksheetOptions>
                    </x:ExcelWorksheet>
                </x:ExcelWorksheets>
            </x:ExcelWorkbook>
            </xml><![endif]-->
        </head>
        <body><table>${str}</table><table>${str}</table></body></html>`

plus.io.requestFileSystem(plus.io.PUBLIC_DOCUMENTS, function(fs) {
    let rootObj = fs.root
    let fullPath = rootObj.fullPath
    console.log(rootObj, fullPath)
    console.log("wancheng2222")
    rootObj.getFile(`data.xlsx`, {
        create: true
    }, function(fileEntry) {
        fileEntry.createWriter(function(writer) {
            writer.onwritestart = (e) => {
                console.log("正在导出")
            }
            writer.onwriteend = (e) => {
                console.log('写入文件成功', e.target.fileName)
            }
            // 写入错误回调
            writer.onerror = function(err) {
                console.error('写入文件失败', err);
            };
            // 写入内容;
            writer.write(template)
        }, function(e) {
            console.log(e.message)
        })
    },error=>{
        
    })
})

plus.io.requestFileSystem 属于html5+ api,请查看下面文档

参考: https://www.html5plus.org/doc/zh_cn/io.html#plus.io.DirectoryEntry.getFile