The corrosion resistance of Q370qENH weathering steel was investigated by using periodic dry/wet alternating salt spray accelerated corrosion tests to simulate marine atmospheric corrosion environment. A comprehensive analysis was performed with analyzing the corrosion rate, rust layer development and phase composition, rust pit morphology and damage tensile property, including corrosive mechanism and characterization. The results show that compared with stress free corrosion, the stress corrosion can significantly improve the corrosion activity of Q370qENH’s surface, thus speeding up the corrosion rate, delaying the formation of stable rust layer to a certain extent and further reducing Q370qENH’s strength. However, no matter whether there is stress or not, the stable protective layer is not formed in the salt spray environment. Q370qENH does not show excellent corrosion resistance in high chloride atmosphere, in which corrosion environment, Q370qENH is not recommended to be used without coating. But Q370qENH still presents a good mechanical properties when with a high level of corrosion.