Abstract: The application of single voltage vector in predictive torque control of multiphase motor models not only has complicated and difficult to adjust weight factors, but also produces serious torque, magnetic chain pulsations and large harmonic currents. In order to solve the above problems, for the control system of dual three-phase permanent magnet synchronous generator(DTP-PMSG), a relative error rate cost function is proposed to eliminate complex and difficult to adjust weight factors, an extended virtual voltage vector and duty cycle optimization strategy are adopted to reduce the torque, magnetic chain pulsations and harmonic currents. In addition, in order to further reduce the harmonic currents brought about by the influence of nonlinear factors such as tube voltage drop, dead zone, and reverse potential in the real situation, the harmonic currents are effectively suppressed by constructing an expanded set of virtual voltage vectors in the harmonic plane. Ultimately, the experimental results confirm the effectiveness and feasibility of the proposed method.