The calculation of fog attenuation empirical model is an important method to predict fog attenuation. In order to apply the fog attenuation empirical model to practice for applicability analysis, based on Mie scattering theory, the attenuation of the laser under different visibility in the Kruse model, Kim model and Ijaz model was calculated using theoretical derivation and simulation analysis methods. The difference between the three models in calculating the attenuation coefficient was analyzed, and the experimental results were compared with the simulation results by building a free-space optical communication experimental platform. The results show that the attenuation results of the 650nm wavelength laser in the fog attenuation channel are closer to the Kim attenuation model. This research conclusion provides a reference for the analysis of the fog attenuation coefficient of the free space optical communication system in Xi’an.