The pulse electro-deposition (PED) has been successfully applied for fabricating nanocomposite layers on the surface of steel substrates. The Ni-AlN nanocomposite layers were fabricated by mixing a given amount of AlN particles in electrolyte ultrasonically. The composition and surface morphology of the layers were investigated by means of XRD and SEM. The results showed that the Ni-AlN nanocomposite layers consisting of nickel grains (~68.27 nm) and AlN nanoparticles (~38.46 nm) had been obtained on the surface of steel substrates by PED. The Ni-AlN layer exhibited a compact surface morphology in micro-regions, and the grain sizes in the Ni layer were greater than that in the Ni-AlN nanocomposite layer.