In order to improve the road adaptability of the wheel-foot hybrid mobile robot, a new power steering system is designed. The reason why the traditional power steering device can not be applied to the wheel-foot hybrid robot is analyzed, and the problem is described. The design requirements of the new power steering system are given, and the structure of a new power steering system is provided. The functions of the system are described. The results show that the system solves the problem that the traditional power steering system can not make the wheels rise and fall by a large margin, and provides a reference for the design of future steering system.