$workbook = new PHPExcel;
$sheet = $workbook->getActiveSheet();
$sheet->mergeCells('A1:E1');

$cell = $sheet->getCell('A1');

// Check if cell is merged
foreach ($sheet->getMergeCells() as $cells) {
    if ($cell->isInRange($cells)) {
        echo 'Cell is merged!'
        break;
    }
}

由于phpexcel存储有关合并单元格信息的方式，我认为没有更好的解决方案.

I think there isn't better solution because of the way phpexcel stores information about merged cells.