<p>Comprehensive microscopic characterization and property tests were conducted to explore the effects of different Cu additions on the evolution of the microstructure of Fe-10Mn-3Al steel and its corrosion properties. The researches demonstrate that Cu addition enhances the surface microhardness and corrosion resistance of medium manganese steel. As Cu addition, the formation of retained austenite is promoted with little effect on the microstructure. Simultaneously, the corrosion resistance is enhanced and the probability of pitting corrosion is decreased. During corrosion, the composition of corrosion products in medium manganese steel was optimized with Cu addition, promoting the development of stable substances and increasing their proportion in the corrosion products, and thus reduces the dissolution and separation of the corrosion products in the formation process. It contributes to improve the corrosion resistance of medium manganese steel, exhibiting good corrosion medium blocking ability and low pitting corrosion tendency.</p>