导出效果如下图所示：

下载xlsx

npm install xlsx

angular.json中引入：

 "node_modules/xlsx/dist/xlsx.full.min.js",
              "src/assets/js/jszip.js",
              "src/assets/js/xlsx.js"

 两个插件地址：

 上传中，等下更新

 typings.d.ts中需要加一下声明

ts代码：

export(){
  var wb = XLSX.utils.table_to_book(document.getElementById("tableDataId"), { sheet: "Sheet JS", raw: true });

    let range = XLSX.utils.decode_range(wb.Sheets['Sheet JS']['!ref']);
    // let borderStyle = {
    //   top: {
    //     style: "thin",
    //     color: { rgb: "000000" }
    //   },
    //   bottom: {
    //     style: "thin",
    //     color: { rgb: "000000" }
    //   },
    //   left: {
    //     style: "thin",
    //     color: { rgb: "000000" }
    //   },
    //   right: {
    //     style: "thin",
    //     color: { rgb: "000000" }
    //   }
    // }
    // wb.Sheets['Sheet JS']['!rows'] = [{ hpx: 150 }, { hpx: 50 }, { hpx: 50 }, { hpx: 50 }, { hpx: 50 }, { hpx: 50 }]
    const numColumns = 100;
    wb.Sheets['Sheet JS']['!cols'] = Array(numColumns).fill({ wpx: 160 });
    wb.Sheets['Sheet JS']["!merges"].forEach((item: any) => {
      if (item.e.r == item.s.r && item.e.c != item.s.c) {
        // 列合并
        let R = item.s.r;
        let countLength = item.e.c - item.s.c;
        for (let i = item.s.c; i <= item.e.c; i++) {
          let cell = { c: i, r: R };
          let cell_ref = XLSX.utils.encode_cell(cell);
          if (!wb.Sheets['Sheet JS'][cell_ref]) {
            wb.Sheets['Sheet JS'][cell_ref] = { t: "s", v: "" };
          }
        }
      } else if (item.e.c == item.s.c && item.e.r != item.s.r) {
        // 行合并
        let C = item.s.c;
        let countLength = item.e.r - item.s.r;
        for (let i = item.s.r; i <= item.e.r; i++) {
          let cell = { c: C, r: i };
          let cell_ref = XLSX.utils.encode_cell(cell);
          if (!wb.Sheets['Sheet JS'][cell_ref]) {
            wb.Sheets['Sheet JS'][cell_ref] = { t: "s", v: "" };
          }
        }
      }
    })
    console.log();
    for (let C = range.s.c; C <= range.e.c; ++C) {
      for (let R = range.s.r; R <= range.e.r; ++R) {
        let cell = { c: C, r: R };
        let cell_ref = XLSX.utils.encode_cell(cell);
        console.log(wb.Sheets['Sheet JS'][cell_ref]);
        wb.Sheets['Sheet JS'][cell_ref].s = {
          alignment: {
            horizontal: 'center', // 水平居中
            vertical: 'center', // 垂直居中
            wrapText: 1, // 文本自动换行
          },
          font: {
            name: "黑体",
            sz: "15",
            bold: true
          },
          // border: borderStyle,
        };
      }
    }

    var wopts = { bookType: 'xlsx', bookSST: false, type: 'binary' };
    var wbout = XLSXX.write(wb, wopts);// 使用xlsx-style 写入
    saveAs(new Blob([s2ab(wbout)], { type: "" }), this.selectTitle[this.selectTitle.length-1]+".xlsx")

    function s2ab(s: any) {
      var buf = new ArrayBuffer(s.length);
      var view = new Uint8Array(buf);
      for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;
      return buf;
    }
}

html:

<table id="tableDataId">
   <tr></tr>
<table>