Abstract: Electroplating Ni-W coatings were prepared on medium carbon steel substrate.Preparation technique was studied through orthogonal experiment design method, using poor analysis method to analyze the various factors affecting the performance of alloy coatings, solution formula and optimum process conditions. Composition, microstructures and performance were analyzed by scanning electron microscope, x-ray diffraction, optical microscopy and microhardness tester. The results show that of all the factors affecting the microhardness, NaI content is the strongest, and followed by current density. The surface of Ni-W alloy coatings is not found to have obvious flaws and has a good bond with the matrix. The microhardness of the coatings can reach 650 HV.