A system of phase stabilized distribution of millimeter wave local oscillator is proposed,which is based on the principle of Michelson interferometer.In the system,the signal phase drift during transition is modulated on the reflected optical signal,which is later coherent heterodyne with reference signal to control the fiber stretcher.Then system phase can be corrected and the phase of output millimeter wave can keep stable.Based on the theoretical model and experimental system,the relationship of phase drift of local oscillator,the length drift of optical fiber and coherent heterodyne output signal are measured.The experimental results agree with the theoretical model,which indicates that the proposed system is feasible.