The invention provides an SCSI drive side and an I/O request control method. The control method comprises the steps of obtaining corresponding physical block addresses according to logical block addresses in multiple received I/O requests, wherein the I/O requests are data access requests for logical blocks in multiple logical spaces in an SAN storage system; merging the I/O requests corresponding to the continuous physical block addresses according to the continuity of the physical block addresses; gathering the merged I/O requests in an SCSI order to be sent to the SAN storage system. By adopting the mode, the I/O requests distributed in different logical spaces can be merged, accordingly the merging possibility of multiple I/O requests during data access is improved, interaction of the I/O requests in a transmission path is reduced, and the access performance of the I/O requests is remarkably improved.