To actualize precise polishing of silicon modification layer on space silicon carbide mirror, combined type polishing technology, consisting of computer-controlled optical surfacing (CCOS), flexible chemical mechanical polishing (FCMP) and ion beam figuring (IBF), is presented. The polishing principles, polishing machines, polishing experiments and polishing functions of three type polishing technologies are introduced, respectively. To improve figure accuracy and reduce surface roughness of silicon modification layer in a way, computer-controlled optical surfacing technology is adopted. The surface roughness and surface finish of silicon modification layer are improved further by flexible chemical mechanical polishing technology. The high figure accuracy of silicon modification layer is achieved finally by ion beam figuring technology. The surface modification silicon carbide plane mirror for space camera is polished by the combined type polishing technology. After polished, root mean square values of the figure and roughness of the space silicon carbide mirror are 0.014λ (λ=0.6328 μm) and 0.71 nm, respectively.