In the PWM drive motor system, high frequency vibration occurs when the power element switches. Aiming at the problem of high frequency vibration in multiphase linear motor, carrier phase shifting technique is proposed to reduce noise. First, according to the relationship between the motor vibration and the magnetomotive force, The formula for calculating the MMF is deduced. The conclusion is that the amplitude of the high frequency component of the motor synthesis magnetomotive force is effectively counteracted by adjusting the carrier shifted angle. The option of the optimal phase shifting angle is analyzed, and finally the conclusion that 180° is the optimal shift angle is verified by simulations.