Abstract: In order to study the effect of the fog particles scattering on laser guidance and improve the guidance precision of guided weapons,based on Mie theory,considering the particle size distribution function,the scattering model of the group particles was obtained.With the help of the model,the relationship between the target position deviation angle and the scattering intensity was obtained and the effect of scattered light on the signal was analyzed from the view of scattering.The calculation showed that the echo signal was influenced obviously by the backscattered light from the atmospheric particles at a certain scale distribution.The results are valuable for the study on the effect of back scattering of atmospheric particles on the laser-guided precision.