In order to address the problem that helical gears of mine-used vibrating screen exciter is prone to wear and and seriously affects the coal washing process, this paper establishes a dynamic numerical simulation model of the coupling system between the helical gear and rotor of the vibrating screen exciter. The fourth order Runge Kutta method is used to solve the time-varying meshing force of the gear. The characteristics of gear wear under mixed elastohydrodynamic lubrication is analyzed. By combining the above methods, the vibration response of the exciter helical gear system is obtained caused by tooth surface wear. Thus, the vibration response characteristics caused by wear faults are obtained, providing a theoretical basis for the diagnosis of gear wear fault in the vibrating screen exciter.