Numerical analysis of scattering properties of three types, nine kinds of aerosols such as continental, maritime and polar type was carried out based on the software package of optical properties of aerosols and clouds. The influence of different aerosol compositions of different types on the scattering properties of aerosols was analyzed. The scaling law about scattering aerosol optical depth varies with wavelength and relative humidity is established. The power-law wavelength dependence of scattering aerosol optical depth is not satisfied at all available wavelength, and different aerosol types have differently suitable wavelength range. Aerosol composition has a great influence on the wavelength and relative humidity change law of scattering aerosol optical depth. The scaling law of scattering aerosol optical depth varies with wavelength and relative humidity can provide reference for the study of the equivalent optical properties of non-uniform aerosol particles and laser engineering applications.