Abstract: China's first scheduled Mars exploration mission will be implemented in 2020,achieving the goal of surrounding, landing,and patrolling in one step. Among them,after the lander softly landing on the surface of Mars,whether the rover can be safely transferred to the surface of Mars along the transfer ramp is the key to the mission success. Based on the functional requirements of the rover's transfer ramp. In this paper, a two-way pumping ramp scheme is proposed,which solves the key problems of large exhibition ratio, drive sharing and reliable deployment, and its unfolding principle and mechanical characteristics are analyzed. The unfolding test in the simulated martian gravity environment is carried out to provide reference for the design of the Mars transfer ramp in China.