Laser communication based on cat′s eye modulating retro-reflector has a faster communication rate than other retro-reflected modulation communication,because the cat′s eye structure can achieve a smaller matching modulator.Based on the Collins diffraction integral formula,the cat′s eye laser echo receiving power through atmospheric attenuation is obtained.Furthermore,combined with the photodetector noise and atmospheric turbulence,the effects of communication distance,turbulence intensity,laser wavelength,incident angle,cat′s eye aperture and receiving aperture on the signal-to-noise ratio of the receiving end are simulated.