In a method for controlling a SAS expander to electronically connect to a RAID card in an electronic device, a plurality of different types for RAID cards, and configuration parameters of the SAS expander corresponding to each type of the RAID cards are preset. Information of the RAID card is read if the SAS expander is electronically connected the RAID card. The method further determines whether the RAID card matches the SAS expander. If the RAID card does not match the SAS expander, the configuration parameters of the SAS expander corresponding to the RAID card is read, and the read configuration parameters and the read information of the RAID card are written into a firmware file in the storage system. The method further stores the firmware file into a flash memory of the SAS expander.