According to the environmental requirements of self-cleaning quality for outdoor lighting system, the refractive index of composite film and the quality ratios were analyzed and simulated based on the theory of optical thin film. The method of electron beam evaporation was used to plate the Ti02/A1203 composite film, and then the composite film was given for the vacuum annealing treatment. By controlling the beams of the left and right of the electron gun, the different mass ratios plating composite film was prepared in the single-crystal control system. The hydrophilic test and the Methyl orange experiment shows that, the higher the quality ratio of Ti02 is, the better the self-cleaning effect is, but the ability of hydrophilic and visible light transmittance are both reduced. The composite film with different quality ratios were tested and analyzed. And the paper adjusts the mass ratio to optimize the test plan, the results show that, when the mass ratio of the Ti02/A1203 is 9∶1, the film not only has a self-cleaning hydrophilic interaction, but also with a high visible light transmittance.