Objective To study the atmospheric corrosion of galvanized steel at Hongyanhe nuclear power station with high SO2 concentration and high Cl- concentration. Methods The galvanized steel was exposed at Hongyanhe atmospheric environment for 4, 12,18 and 24 months, according to GB/T 64-1997. The corrosion behavior of galvanized steel after explosion was investigated by corrosion mass loss test, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results The results of corrosion kinetics analysis show that the galvanized steel corrosion weight loss is linear increase with the increase of the exposure time. XRD analysis results show that with the extension of exposure time, zinc coating on the surface of the formation of the corrosion product composition didn’t change much, which were mainly Zn12(SO4)3Cl3(OH)15?5H2O and 6Zn(OH)2?ZnSO4?4H2O. SEM results show that the corrosion products with the extension of exposure time increases gradually, the product morphology changes slightly, with ball and needle. From the point of cross section analysis, after 18 months, corrosion products were divided into two layers, while after 24 months, the thickness of the corrosion products increases slightly, loose layer transformed into dense layer. Conclusion SO2 and Cl- are the main factors that influence the corrosion process. The corrosion products formed on the surface of galvanized steel have certain protective effect.