Electromagnetic gear realize non-touching driving technology, which is non-friction and non- lubrication. Based on the FEM static analysis, creating torsional vibration dynamic model for the electromagnetic gear system with the theory and method of mechanical vibration to makes research on the dynamic performance parameter. The system makes motion stimulation by utilizing the Simulink module of MATLAB. Then, a conclusion is made through the theoretical analysis. The analysis provides some reference for the futher study of the dynamic characteristics of the magnetic gear driving system.