A system for testing hard disks includes a hard disk testing device and a computer. The computer has a mainboard and a key-press controller. The hard disk testing device connects with the mainboard and includes: a hard disk interface configured for connecting one or more hard disks to be tested to a south bridge of the mainboard; a key-press panel configured for connecting the key-press controller of the computer, and providing a hard disk testing control interface for users; and a hard disk testing unit configured for testing the one or more hard disks.