In order to study the dynamic characteristic of the escalator drive chain system and the effect of the sprocket wear and chain wear on the characteristic of chain drive,based on the theory of chain drive kinematics and multi-body dynamics,a simulation model of the escalator drive chain system is built by RecurDyn.Two conditions of no-load and load are set up,and the simulation analysis is made under the condition of adding wear fault. The changing characteristic of the chain drive under the normal condition and the wear condition is obtained. The results of analysis show that the dynamic load increases significantly after wear. Some reference for the study of the wear mechanism of escalator drive chain system and fault diagnosis can be provided by this method.