Abstract: Dual three-phase permanent magnet synchronous motor (DTP-PMSM) has received extensive attention because of its advantages of low torque ripple, and fault tolerance ability and is suitable for low-voltage and high- power output occasions. By remodeling the post-fault DTP- PMSM system under single phase open-circuit fault based on virtual healthy model, it is pointed out in this paper that neglecting the voltage constraint in the design procedure of the fault-tolerant controller will cause current distortion and torque ripple. Furthermore, in order to optimize the performance under post-fault operation, a control algorithm is designed based on the proposed model to compensate for the voltage constraint. The proposed control strategy retains the advantages of the virtual healthy model with only three current loops, and realizes the torque ripple suppression under post-fault operation. This method ensures high performance operation of the DTP-PMSMs under open circuit faults. Simulation and experimental results also prove the accuracy of modeling and the effectiveness of the proposed strategy in reducing harmonic loss and suppressing torque ripple.