After making analysis of Rayleigh noise characteristics in an optical fiber gyroscope, we developed a new method to suppress the noise. Theoretically, we found that with this method the Eayleigh noise can be suppressed by a factor of |Jo(φm)|, here J0(x) is the zeroth-order Bessel function and φm the modulation amplitude. Therefore, with a proper modulation the noise can be reduce to zero. This new method is simpler and more effective than that using band-pass noise phase modulation.