To solve the instability of track robot in the process of climbing obstacles, a track robot with passive rocker was designed and the three-dimensional model of the robot was built by UG in this paper. Furthermore, the detailed skid theory analysis during climbing stair was made. The virtual prototype kinematics simulation for this robot was made by using the tracked vehicle subsystem of RecurDyn. The theory analysis and the simulation results verify the feasibility of the machine and provide some theoretical guidance for developing the obstacle performance of track robot.