For some adaptive optics (AO) systems, one deformable mirror (DM) can not meet the need of large stroke and high spatial frequency. In this paper, a double DMs way is present. In this system, a large stroke DM (LSDM) with low spatial frequency corrects low order aberrations and a high spatial frequency DM (HSFDM) with small stroke corrects high order aberrations. The decoupling algorithm of two DMs is essential for working properly. In this paper, a decoupling algorithm and experimental results for a double DM AO system are presented. The result indicates that the compensation result of double DMs AO system is almost the same as that of the conventional AO system using single DM with ideal stroke and equivalent spatial frequency.