A method for testing hard disks under an extensible firmware interface (EFI) provides a device tree of hard disks. Nodes of the device tree represent block devices or file systems of the hard disks. Devices paths and handles corresponding to each of the device paths are obtained from the device tree. Parent controller handles of each of the device paths are obtained. If there are parent controller handles the same as the obtained handles, the parent controller handles the same as the obtained handles are deleted. The computer determines that a number of the hard disks is equal to a number of the device paths corresponding to the remained parent controller handles. Nodes information of each of the device paths corresponding to the remained parent controller handles are determined as hard disk information of each of the hard disks.