In order to meet the requirements of rapid evaluation of high-energy lasers for practical applications, this paper constructs scaling laws for Gaussian beams propagation through the atmosphere. Firstly, the beam spreading due to single effects including diffraction, optical turbulence and thermal blooming is scaled to identify suitable scaling factors. Then, the scaling functions of the effective radius with multi-effect interaction are established step by step, and the scaling exponents are fixed by genetic algorithm. Finally, the scaling laws of the far-field mean intensity of high-energy laser propagating through atmosphere are constructed. Comparison with the simulations in given scenarios reveals the mean relative error of the scaled mean intensity.