A novel structure of a six-wheel all-terrain mobile robot with the integration of active and passive control is presented in this paper. According to different complex terrain environments, three-dimensional simulation models of the six-wheel all-terrain mobile robot were built using ADAMS software and the dynamic simulation analyses under different terrain conditions were accomplished. Using the ADAMS model, the kinematic and dynamic characteristics curves of the whole robot and parts of robot were obtained. The simulation analyses provide the theoretical basis for the optimization of the mechanical structure, control system design and the selection of drive motors. Simulation results show that the structure of this kind of robot has good mobility and obstacle-climbing performance.