In the view of meshing impact during the operation of food conveyor chain drive,based on Hertz contact theory,the amplitude and expression of the impact force of the driving sprocket are given by building the nonlinear spring damping dynamics model of meshing impact. With the help of dynamics simulation software ADAMS,the simulation and research of the meshing impact at different speed on the system is carried out,the change law of the contact force between the sprocket and the roller is obtained,and the simulation results meet with the actual working condition and high reliability. The compare between simulation results and theoretical calculation results prove the relative error between theoretical value and simulation value is reasonable,and the dynamics model is reliable.