Abstract: In this paper,the human bodys movement is divided in to the stable equlibrium state and the unstable equlib rium state by analyzing the equlibrium states of object on the bottom.It is the theoretical basis foranalyzing the stable gaits of the two-legged mechanism.Using Multi-Rigid-Dynamics method,theZMP(Zero Moment Point) of the model is calculated without balancing,and its moving stability is analyzed.A double balancing method of the inclined foot and swing head mechanism is adopted,and the stablemoving gaits are obtained.The result has been verified by experiments.