Abstract: Corrosion behavior of 2205 duplex stainless steel (2205 DSS) in a bromine-containing acetic acid environment was studied by chemical immersion method, combined with color metallographic technology, corrosion weight loss test, scanning electron microscopy in-situ analysis, and energy spectrum analysis. The results show that the selective corrosion of austenite occurred in 2205 DSS in the bromine-containing acetic acid environment. The corrosion rate of 2205 DSS increased with increasing temperature and Br^- amount, and decreased with increasing immersion time.