Abstract: The navigation on Mars mainly depends on the assistance of the earth-based deep space exploration network,and the accuracy of optical imaging autonomous navigation technology is unsatisfactory. One method based on formation flying satellites(FFS)to autonomously determine the position and velocity is proposed in this paper. The measurement information includes the inter-satellite position and the absolute attitude. As the measurements are combined with the dynamics of formation satellites,the Extended Kalman filter(EKF)is used to optimally estimate the states. Relevant system parameters are optimized with intelligent optimization methods. The results show that the position accuracy can reach 10 m and the velocity accuracy can reach 0.01 m/s.