Abstract: In order to analyze the relationship between the laser propagation and atmospheric parameters like visibility and refractive index structure constant and laser beam parameters like the wave length and waist width, the propagating law and the influence on the laser intensity was studied based on the Gaussian beam. The results indicates that if the parameters of the laser source and atmosphere are confirmed, the effect of laser propagation is easy to know, which could provide a rule for the feasibility of laser engineering application, as well as conduct laser system design optimization.