Abstract: Size of nanostructured Fe grain is much smaller than that of ordinary ones, which causes higher hardness, higher strength and better wear resisitance. Therefore nanostructured-Fe flim, growing up on the surface of ordinary Fe, can be used as wear resisitant layer. Nevertheless, nano-Fe is very high in its activity for the reason of its numerous boundaries. According to the traditional theories of corrosion, grain boundaries are active zones, which causes that nano-Fe is easier to corrosion than ordinary ones. After treatment with Aluminium diffusion in nano-Fe film, reducing activity of grain boudaries, raising wear resistance of nano-Fe film was proved by practice. The performance is equivalent to premium steel plates of high strength and wear resistance, but with high cost. SIMS (secondary ion mass spectrometry) was used for depth profiling of thermal diffusion of Al in nano-Fe film in this experiment. The depth of Aluminium diffusion in nano-Fe film is much deeper than normal-Fe.