Aiming at the problem of large common-mode voltage in model predictive torque control of permanent magnet synchronous motor, the common-mode voltage suppression effectiveness of three methods, namely, joint control of flux linkage, torque and common mode voltage, direct removal of zero voltage vector and virtual zero voltage vector, is analyzed comparatively. Simulation results show that all three methods can effectively suppress the common-mode voltage. The first two methods do not use zero voltage vector, resulting in increased flux linkage ripple and torque ripple. Virtual zero voltage vector method retains the zero voltage vector and effectively suppresses the common-mode voltage, but the switching frequency increases. Adaptive dynamic virtual zero voltage vector method selects the zero voltage vector generation method with the smallest number of switching times, which can effectively reduce the switching frequency under the premise of the basically equivalent control performance, with the optimal overall performance.