Effects of nitriding modification on surface phase structure,morphology,corrosion resistance and magnetostriction of (Tb,Dy)Fe2 alloy were investigated by nitrogen ion implantation.Results showed that the surface REFe2 phase gradually decomposed and transformed into REN,α-Fe and Fe8N phases with the increase of nitrogen ion implantation dose.The surface morphology of the alloy had an obvious change after nitrogen ion implantation.The corrosion resistance properties of the alloy in acidic,alkaline and chloridion environment were also greatly improved.In addition,the magnetostriction performance of the alloy was almost not affected by ion implantation as the nitrided layer was quite thin and the operating temperature was very low.The results proved that nitrogen ion implantation was an effective method for surface modification of (Tb,Dy)Fe2 alloy.