To improve the torque performance of five phase permanent magnet synchronous motor under fault condition, a decoupling fault tolerant control method based on minimum copper loss was proposed. The method which based on the principle of the constant stator magnetic motive force and minimum copper loss could be used to calculating the faulttolerant current. Then, according to the compensation current, the reducedorder transformation matrix had been deduced. In the rotating coordinates, the mathematical model of the fivephase permanentmagnet synchronous motor was established. And the decoupling vector control method is achieved. The effectiveness of the proposed faulttolerant control algorithm is verified by the method of cosimulation. The results of the simulation showed that the proposed faulttolerant control could reduce the torque ripple under the faulty condition.