In order to solve the problem of many iterations in traditional model predictive current control, improve the flexibility of two degrees of freedom about direction and amplitude in voltage vector synthesis of dual three-phase motor, and reduce the output torque ripple and current ripple, a dual second-order model predictive control algorithm based on current loop optimization is proposed. Compared with the conventional speed loop using the PI control algorithm and current loop using the traditional MPC control algorithm, this algorithm adopts the second-order MPC control mode in the speed loop, which reduces the speed regulation time and increases the motor immunity; The second-order MPC control mode is adopted in the current loop, and the traditional iterative calculation method is improved to calculate the direction and amplitude of the output voltage vector through the analytic function, which increases the flexibility of the output voltage vector. Four vector SVPWM is used to modulate the voltage vector to reduce the current amplitude in the harmonic subspace. The simulation results show that the algorithm can significantly reduce the torque ripple and current ripple, and increase the transient performance of the motor.