The direct drive torque motor is affected by the cogging torque,torque ripple and other inherent characteristics in the movement process,which would produce position error,and the accuracy would further decline due to the influence of variable load.In order to reduce the position error,fractional order sliding mode control method was used，the models of fractional order sliding mode direct drive torque motor and PID direct drive torque motor were established;the torque of cam machining was collected as variable load data inputting model for simulation.The simulation results show that compared with the PID control method,the position accuracy of the fractional order sliding mode control method is improved by about 25% and the speed is improved by about 3548%;by using the fractional order sliding mode control method,the control accuracy of direct drive torque motor can be improved.