A novel flexible restrict reducer is proposed. This reducer is a two stages conical cylindrical gear reducer. The setting element of conical gear and cylindrical gear is pre-tighten belleville spring. There is no axial movement of the gears while the gear axial force is lower than the spring force,the location is accuracy.On the contrary,the spring deforms for absorbing energy to avoid permanent deformation applied by direct axial force. The 3 D model of the flexible restrict reducer is built by UG 8. 0 and the transient dynamics analysis under specified load is carried out by the ANSYS Work Bench. The theoretical feasibility of flexible restrict reducer is verified by the simulation result.