This paper presents a design method of flux-switching permanent magnet machine to reduce acoustic noise and mechanical vibration. A main source of noise and vibration in electric motor is radial magnetic force. Mechanical vibrations are generated by electromagnetic interference between harmonic components of radial magnetic force and mechanical resonance frequencies of structures of the motor. Then, the motor design has to be considered to reduce the amplitude of radial magnetic force harmonic. The radial magnetic force is calculated by finite element method and Maxwell stress tensor. The harmonic components of radial magnetic force are examined by Fourier decomposition.