To improve the product quality of automatic packaging production line, a new strategy of torque duty ratio control based on improved voltage vector selection rules is presented to solve the high torque ripple due to the structure of switched reluctance motor (SRM). First, based on the previous voltage vectors selection table of direct torque control in 12 sectors, a new increasing torque vectors selection rule is proposed to reduce the torque ripple at commutation intervals. The decreasing torque vectors which produce no negative torque are also adopted to enhance torque-per-ampere. Second, a new method of torque duty ratio control is designed. By estimating the torque in next period, the actuation duration of voltage vectors can be determined, so that the output torque will track the torque reference as rapidly and steadily as possible. Finally, through building a model of proposed method in Matlab/SIMULINK environment and comparing with models of both the model predictive direct torque control and the torque duty ratio control based on direct demagnetization vectors selection table, the results show that the torque ripple of proposed method can be decreased by 31% to 57% than the other two methods. The torque-per-ampere of proposed method can be increased by 35% to 44% than model predictive direct torque control and be decreased only by 1% to 2% than the other method. By using the proposed method, SRM will run more smoothly and efficiently.