Abstract: A method for processing a bad block in a redundant array of independent disks (RAID) is presented, which is characterized by a software RAID constructed by a scale computer interface disk, and adapted to backup data in a bad block in the software RAID. The method includes invoking an access error program to intercept an access instruction for a data block in the software RAID when the data block is a bad block; searching a disk number and a logical block address of the data block in the software RAID according to the access instruction; selecting the scale computer interface disk; and mapping data stored in the data block, the disk number, and the logical block address to a reserved local memory of the scale computer interface disk. Through the above steps, the data in the bad block can be mapped to a normal block, thus maintaining the data integrity.