Abstract: Based on multiple RAID controllers system，this paper presents a RAID50 massive storage model.First，build hardware RAID5s of the same type on every single RAID controller，all of which have the same disk type and disk number.Secondly，regard each RAID5 as a single disk，and combine them to be a RAID50 by using software.By adopting a two level concurrency data partioning and placing method and set extended data block，which equals to a data parity group of RAID5 in a RAID controller，as the transmission granularity between Cache and RAID system，this paper carries out the full concurrency access of the m*n disks of RAID system.The two level address mapping algorithm and the best-fit algorithm of logic volume management are designed.The theoretical analysis and test results show that the method has reduced the I/O response time of the system greatly and obtained massive logic volume capacity and I/O performance which are related to the number of channels.