A disk control apparatus for performing parallel data transfer between a host processor and N number of disk devices. The disk control apparatus includes N number of disk control units for controlling writing and reading of data into and from the disk devices, N number of buffer control units, each having a data buffer for storing data to be written into the disk device and data read from the disk device, and a main control unit for controlling the parallel data transfer between the host processor and the N number of buffer control units. The disk control apparatus further includes a sequential number generating unit and a check code generating unit for applying a sequential number and a check code to data to thereby write the data into the disk devices, and a comparator unit operative when transferring data stored in the data buffers which is read from the disk devices through the disk control unit for comparing sequential number and check code read from the data buffers with the sequential number and check code generated from the sequential number generating unit and check code generating unit.