Abstract: In order to solve the problems of torque ripple, high computational complexity and difficulty in adjusting the weight coefficient of permanent magnet synchronous machine (PMSM) with traditional single- vector model predictive torque control(MPTC) strategy, in this paper, a fast method for selecting the optimal vector based on the amplitude of voltage vector was proposed. The reference voltage vector was predicted directly by deadbeat predictive torque control, which eliminated the weight coefficient in the evaluation function. The change trend of basic voltage vector under the condition of variable bus voltage was analyzed, and the sector subdivision was also proposed for deduction of the vector selection method under different voltage ratio. All the basic voltage vectors of the open-winding PMSM topology with double power supply were fully considered, and the optimal vector selection method in different sectors was established by using the method of switch table, which reduced the computational complexity of the algorithm, and thus the torque ripple of the motor is effectively improved. The experimental results show that the proposed single vector MPTC predictive torque control strategy can achieve a good motor control effect in a wide bus voltage ratio range.