Direct wavefront gradient algorithm directly establishes correspondence between measurands of the wavefront sensor and response characteristics of the deformable mirror. The voltage can be directly calculated by the algorithm. We use Hartmann wavefront sensor with 64 sub-apertures to detect the distorted wavefront. Based on the hypothesis that of deformable mirror is the weighted addition of the influence function, each of the voltage values applied on the drive is solved by the algorithm. The simulated 32 units of deformable mirror can be controlled and then distorted wavefront can be restored. The simulation result shows that direct wavefront gradient algorithm can effectively adjust the distorted wavefronts.