For　the　problem　of　autonomous　optical　GNC　for　soft　landing　on　asteroid,　a　method　based　on　constrained　MPC　(Model　Predictive　Control)　is　proposed　in　this　paper.　First,　introduce　the　strategy　of　soft　landing　on　asteroid　based　on　autonomous　optical　system.　Second,　the　desired　trajectory,　position　and　velocity　that　satisfy　the　requirement　is　planned.　Third,　the　control　method　of　constrained　MPC　and　EKF　is　applied　to　ensure　the　fast　and　accurate　response　to　the　robustness　of　guidance　law.　Finally,　a　serious　of　comparison　with　PD　and　VSC　are　conducted　to　test　the　performance　of　MPC.