Abstract: In order to get stable and natural gait of numerical man with lower exoskeleton in the dynamic simulation of virtual man-machine system, the study of gait planning methods is required. The gait of numerical man was planned and simulated in the environment of Matlab and Adams by dynamics model method and passive dynamics method respectively. The simulation results show that both methods are practicable in the dynamic simulation of virtual manmachine coupling system. The former method performs a high stability gait, while the later has a more efficient and natural gait.