The optimal voltage vector selection strategy was proposed for the problem of unreasonable torque ripple in direct torque control of surface permanent magnet synchronous motor realized by traditional switch table. According to the law of voltage vector and flux linkage, the voltage vector selection interval table was obtained, and the cost function of flux linkage and torque error was established. Based on the predictive control, the voltage vector in interval was selected optimally, and achieved by the space vector modulation technique. The simulation results showed that the optimal voltage vector selection strategy proposed can completely eliminate the unreasonable torque ripple caused by the improper selection of the voltage vector of the switch table, the average error of the torque was reduced by 58% and the peak error was reduced by 67%, the average error of the stator flux decreases by 28% and the peak error was reduced by 53%. At the same time, the use of space vector modulation technology makes the inverter switching frequency constant.