Abstract: NiCrBSi series self-fluxing alloy coating was prepared on the surface of 20G steel by supersonic flame spraying, and then the surface coating was remelted by high-frequency induction remelting technology.In order to study the corrosion resistance of nickel-based coating, the phase composition, component distribution and corrosion parameters of the coating were analyzed by using 20G steel commonly used in boiler as the control, using the method of electrochemical testing and combining with the analysis techniques of X-ray diffraction(XRD)and energy dispersive spectroscopy(EDS).The results show that the coating of nickel-based molten alloy prepared by induction welding technology is dense.After induction remelting, the layered structure in the coating is eliminated, and a metallurgical bond is formed between the coating and the substrate.Compared with 20G, the prepared nickel-based coating has lower corrosion current density and higher polarization resistance, indicating that the nickel-based coating as a protective layer significantly improves the corrosion resistance of 20G.