将数据导出到Excel的方法有多种，速度有快慢之分，我用过三种方法，速度都比较快，下面的一种利用Excel内置的功能，是三种之中最快的。其中最主要的是下面两句：
    xlQuery := xlSheet.QueryTables.Add(ADOQExport.Recordset ,xlSheet.Range['A3']);
    xlQuery.Refresh;
　　不过我这里稍为复杂一点，要通过某种条件完成分类汇总。

function ExportToExcel: Boolean;
var
  xlApp, xlBook, xlSheet, xlQuery: Variant;
  SQLCmd: String;
  i, iNextRow: Integer;

  //设定单元格默认格式
  procedure ExcelSetDefaultFormat;
  begin
    xlSheet.Cells.Font.Name := '宋体';
    xlSheet.Cells.Font.Size := 12;
    xlSheet.Cells.VerticalAlignment := 2;
    //xlSheet.Cells.RowHeight := 17.25;
    xlSheet.Range['C:D'].HorizontalAlignment := xlCenter;
  end;

  //输出标题
  procedure ExcelSetHeader;
  begin
    xlSheet.Range['A1'].Value := '显示在报表第一行的标题';
    xlSheet.Range['A1:F1'].HorizontalAlignment := 7;
    xlSheet.Range['1:1'].Font.Size := 18;
    xlSheet.Range['1:1'].Font.Bold := true;
    xlSheet.Range['A2'].Value := '文件编号：WL/B 19';
    xlSheet.Range['A2'].Font.Size := 11;
    xlSheet.Range['F2'].Value := '记录编号：GZ-023';
    xlSheet.Range['F2'].HorizontalAlignment := xlRight;
    xlSheet.Range['F2'].Font.Size := 11;
    xlSheet.Range['A3'].Value := 'XXXXX有限公司';
    xlSheet.Range['F3'].Value := '日期：2005-X-X' ;
    xlSheet.Range['F3'].HorizontalAlignment := xlRight;
    //输出字段名
    ADOQExport.SQL.Strings[4] := 'where 1=0';
    if ADOQExport.Active then ADOQExport.Requery else ADOQExport.Open;
    xlQuery := xlSheet.QueryTables.Add(ADOQExport.Recordset ,xlSheet.Range['A4']);
    xlQuery.FieldNames := true;
    xlQuery.RowNumbers := False;
    xlQuery.FillAdjacentFormulas := False;
    xlQuery.PreserveFormatting := True;
    xlQuery.RefreshOnFileOpen := False;
    xlQuery.BackgroundQuery := True;
    xlQuery.RefreshStyle := xlOverwriteCells;   //xlInsertDeleteCells;
    xlQuery.SavePassword := True;
    xlQuery.SaveData := True;
    xlQuery.AdjustColumnWidth := True;
    xlQuery.RefreshPeriod := 0;
    xlQuery.PreserveColumnInfo := True;
    xlQuery.Refresh;
    iNextRow := 5;
  end;

  //设置页脚
  procedure ExcelSetFooter;
  begin
    xlSheet.PageSetup.LeftFooter := '制表：' + DM.UserInfo.UserName;
    xlSheet.PageSetup.CenterFooter := '审核：';
    xlSheet.PageSetup.RightFooter := '第 &P 页，共 &N 页';
  end;

  //输出汇总数据
  procedure ExcelSetSum;
  begin
    xlSheet.Range[Format('A%d', [iNextRow])].Value := '条数合计(条)';
    xlSheet.Range[Format('A%d:B%0:d', [iNextRow])].HorizontalAlignment := 7;
    xlSheet.Range[Format('C%d', [iNextRow])].Value := FloatToStr(DBGridEh1.Columns[6].Footer.SumValue);
    xlSheet.Range[Format('C%d:F%0:d', [iNextRow])].HorizontalAlignment := 7;
    xlSheet.Range[Format('A%d:F%0:d', [iNextRow])].Font.Bold := true;
    Inc(iNextRow);
    xlSheet.Range[Format('A%d', [iNextRow])].Value := '重量合计(kg)';
    xlSheet.Range[Format('A%d:B%0:d', [iNextRow])].HorizontalAlignment := 7;
    xlSheet.Range[Format('C%d', [iNextRow])].Value := FloatToStr(DBGridEh1.Columns[7].Footer.SumValue);
    xlSheet.Range[Format('C%d:F%0:d', [iNextRow])].HorizontalAlignment := 7;
    xlSheet.Range[Format('A%d:F%0:d', [iNextRow])].Font.Bold := true;
  end;

  //根据类别输出数据到Excel
  procedure ExportData(DataType: Byte);
  begin
      SQLCmd := Format('where DataType=%d ', [DataType]);
      ADOQExport.SQL.Strings[4] := SQLCmd;
      if ADOQExport.Active then ADOQExport.Requery else ADOQExport.Open;
      ProgressBar1.StepIt;

      if not ADOQExport.IsEmpty then begin
        //标题
        xlSheet.Range[Format('A%d', [iNextRow])].Value := DM.GetDataTypeStr(DataType);//将DataType转换为相应的文字显示
        xlSheet.Range[Format('A%d:F%0:d', [iNextRow])].HorizontalAlignment := 7;
        xlSheet.Range[Format('A%d:F%0:d', [iNextRow])].Font.Bold := true;
        Inc(iNextRow);

        xlQuery := xlSheet.QueryTables.Add(ADOQExport.Recordset ,xlSheet.Range[Format('A%d', [iNextRow])]);
        xlQuery.FieldNames := false;
        xlQuery.Refresh;
        Inc(iNextRow, ADOQExport.RecordCount);
        xlSheet.Range[Format('A%d', [iNextRow])].Value := DM.GetDataTypeStr(DataType) + '合计(条)';
        xlSheet.Range[Format('A%d:B%0:d', [iNextRow])].HorizontalAlignment := 7;
        xlSheet.Range[Format('C%d', [iNextRow])].Value := Format('=SUM(C%d:C%d)', [iNextRow-ADOQExport.RecordCount, iNextRow-1]);
        xlSheet.Range[Format('D%d', [iNextRow])].Value := Format('=SUM(D%d:D%d)', [iNextRow-ADOQExport.RecordCount, iNextRow-1]);
        xlSheet.Range[Format('A%d:F%0:d', [iNextRow])].Font.Bold := true;
        Inc(iNextRow);
      end;
      ProgressBar1.StepIt;
  end;

begin
    Result := true;
    ShowProgress(0, cbbDataType.KeyItems.Count*2+2, 0); //调用前面例子中的函数显示进度面板
    Screen.Cursor := crHourGlass;
    try try
        //建立OLE对象
        xlApp := CreateOleObject('Excel.Application');
        xlBook := xlApp.Workbooks.Add;
        xlSheet := xlBook.Worksheets['sheet1'];
        xlApp.Visible := false;
        ProgressBar1.StepIt;
        //设置格式
        ExcelSetDefaultFormat;
        //输出标题内容
        ExcelSetHeader;
        ProgressBar1.StepIt;

        //查询结果，导到EXCEL
        for i:=0 to cbbDataType.KeyItems.Count-1 do  //cbbDataType: TDBComboBoxEh
            ExportData(StrToInt(cbbDataType.KeyItems.Strings[i]));
        //输出汇总内容
        ExcelSetSum;
        //设置边框
        xlSheet.Range[Format('A4:F%d', [iNextRow])].Borders.LineStyle := xlContinuous;
        xlSheet.Cells.EntireColumn.AutoFit;
        //输出页脚
        ExcelSetFooter;
    except
        if not VarIsNull(xlApp) then
        begin
            xlApp.Quit;
            xlApp.Disconnect;
            xlApp := Unassigned;
            xlApp := NULL;
        end;
        result := false;
        Exit;
    end;
    finally
        pnlShadow.Visible := false;
        pnlProgress.Visible := false;
        Screen.Cursor := crDefault;
        xlSheet := Unassigned;
        xlBook := Unassigned;
        if not VarIsNull(xlApp) then begin
            xlApp.Visible := true;
            xlApp := Unassigned;
        end;
        if ADOQExport.Active then ADOQExport.Close;
    end;
end;