Abstract: The simulation of the timeofflight sensor is mainly used to evaluate the processing algorithm of the depth data. Existing simulation models include two types,one is based on a specific noise pattern generated from a threedimensional model of a scene,and the other one is a physical process simulation model based on optical signal propagation. The simulation model of timeofflight imaging is implemented based on physical processes of optical signal propagation. The system is oriented to the needs of engineering applications.The full physical process of timeofflight imaging is modeled, and the simulation parameters are set according to specific sensors.The depth data of the scene is generated the impact of parameter changes on depth data is evaluated and this model is used to analyze typical errors in timeofflight imaging.