The virtual prototype model of automatic feeding mechanism was built by introducing its simplified 3D model established by Pro/E software into the software RecurDyn.The correctness of the prototype was validated by comparing the calculation results of the model and the experimental data.The fault models of chain wheel and barrel meshing area as well as chain wheel and small roller meshing area were built through the fault injection technique.Simulation analysis of fault models was completed，the effect of chain wheel wear on the automatic feeding mechanism was obtained,and the wear threshold in two key areas was determined,which provides an reference for the study of fault mechanism of automatic feeding mechanism.