Abstract: Aiming at the autonomous and the precise navigation of Mars pin-point landing, an autonomous navigation method based on only landmark image is presented in this paper. In order to deal with image-processing time delay, the position and the attitude of detector at the imaging time are used as system state. The current system state can be updated by these landmark measurements through iterated extended Kalman filter. Using the method, the effects of landmark position error on navigation precision are analyzed. Finally, the validity of the proposed navigation method is confirmed by numerical simulations.