The invention relates to the field of programmable logic devices and embedded devices, and in particular relates to a hard disk firmware repairing system and a hard disk firmware repairing method. The hard disk firmware repairing system comprises a PCI-E (programmable communication interface-express) interface, a hard disk power supply controller, a hard disk data interface, a principal computer and a central control chip; the PCI-E interface is respectively connected with the central control chip and the principal computer; the input end and the output end of the hard disk power supply controller are respectively connected to the principal computer and a hard disk, and a control end is connected to the central control chip; a control end of the hard disk data interface is connected to the central control chip, and a data transmitting-receiving end is connected to the hard disk. By adopting the hard disk firmware repairing system, the problem that the hard disk cannot be recognized by the principal computer and the breakdown maintenance or data extraction is difficultly carried out due to the damage of the hard disk firmware or the bad track of the hard disk can be solved; through the control of the hard disk firmware repairing system, the data which is not damaged in the hard disk can be recognized and read, so that the hard disk firmware repairing success rate and the data extracting efficiency can be improved.