Abstract: In adaptive optic system, for correcting the atmosphere turbulence, base on the open-loop atmospheric data, a kind of prediction control algorithm was proposed in this paper to reduce the effect of servo lag. The spatio-temporal recursive least square (RLS) prediction algorithm was used to predict the deformable mirror. The residual error of the adaptive optics system was calculated with and without the prediction control algorithm respectively. The results show that the residual error was reduced effectively with the RLS algorithm.