Objective To optimize the technology with the silane coupling agent KH-550 for surface modification of aluminum alloy and innovatively reduce the ethanol content without affecting the performance, in order to meet the demand of safety and low cost in the industrialized production. Methods The single factor variable method was used to study the effects of silane and ethnol concentration in the solution, curing temperature and curing time on the silane film corrosion resistance, and thus to determine the best formulation process and analyze the surface morphology, composition and hydrophobicity of the silane film. Results The optimized conditions were as follows. The ratio of silane/ deionized water/ ethanol was 5 /55 /40 (V/ V/ V), the curing temperature was 180 ℃ and the curing time was 40 minutes. In these conditions, a complete and even silane film composed of C, O, Si and other elements with good corrosion resistance was obtained. The concentration of silane had a great influence on the corrosion resistance and the contact angle of the silane film which could be up to 70. 2° under the optimum process. Conclusion The silane film has a certain barrier effect for aluminum substrate, protecting the substrate from corrosion.