In adaptive optics system, the effectiveness of wavefront correction is influenced gy the types of wavefront sensor and corrector, their relative configuration (matching) and wavefront reconstruction algorithm. In this paper, the computer simulation experiments for the system using Hartmann –Shack wavefront sensor, deformable mirror with continuous surface plate and discrete actuators, direct slope wavefront reconstruction algorithm are conducted. The principle that each subaperture should be controlled mainly by 3 actuators is concluded.