The relationship of atmospheric visibility to laser intensity was analyzed based on Mie theory under the conditions of single scattering and multiple scattering scenarios in sand and dust weather. An improved analytical expression of laser intensity and atmospheric visibility was derived in single scattering scenario. The multiple scattering was simulated by Monte Carlo method and compared with single scattering. The results show that the received laser intensity will be increased with the increment of atmospheric visibility and approximate to a saturated value when the laser wavelength and transmission distance is constant. Moreover, when the atmospheric visibility remain unchanged, the received laser intensity will be decreased with the increment of laser wavelength, and with the increase of transmission distance, the influence of multiple scattering will become more and more notable.