The work aims to improve the corrosion resistance and adhesion strength with coating on 5182 aluminum alloy. Silane coating was prepared on 5182 aluminum alloy with silane agent KH550. Effects of different immersion time, pH and curing temperature on structure and properties of the silane coating were investigated, and then the preparation process of silane coating was optimized. The structure and composition of the silane coating were studied by scanning electron microscopy(SEM), contact angle tester and Raman spectrum. Electrochemical impedance spectroscopy（EIS）was used to evaluate the corrosion performance of the coating. The automatic scratch tester for coating adhesion was applied to evaluate the influence of silane coating on the adhesion strength of organic coating. The optimum preparation process of silane coating on 5182 aluminum alloy was immersion time of 180 s, pH of 11 and curing temperature of 90 ℃. The silane coating prepared under such process condition was evenly and densely placed on aluminum alloy substrate and about 100 mm thick. In the Na2B4O7×10H2O and NaOH solution, the low frequency impedance of silane treated sample was about 2 orders of magnitude higher than that of un-treated sample. The adhesion property of the silane treated sample to organic coating was also much better than the un-treated sample. The silane coating prepared by optimized process can improve the corrosion resistance of 5182 aluminum alloy as well as the adhesion strength of organic coating to the alloy substrate when used as intermediate layer.