A theoretical study of the algorithm of aberration for a double mirrors adaptive optical system including 37-element OKO deformable mirror and 140-element BMC deformable mirror is presented. By combining the influence function of the two deformable mirrors, a method for aberration correction under combination and dynamic optimization of influence function is proposed. An adaptive optical system using a single 37-element OKO deformable mirror, a single 140-element BMC deformable mirror and two deformable mirrors have been numerical simulated. Results show that the residual aberration by the dynamic optimization method is smaller. It also indicates that the close-loop correction performance of double deformable mirrors is better than that of the adaptive optical system with a single deformable mirror. The method under combination and dynamic optimization of influence function can improve the compensation ability of an adaptive optical system.