Abstract: High strength stainless steel cladding layer was prepared on Crl5Ni4Mo3N substrate by laser cladding technology. Then the microstructure, hydrogen absorption rate, electrochemical impedance and corrosion morphology of the substrate and cladding layer were analyzed and characterized by scanning electron microscope, hydrogen absorption test and electrochemical analyzer. The results show that the corrosion resistance of the cladding layer is worse than that of the substrate. The corrosion mechanism of the substrate and cladding layer was explored. It is found that the corrosion process of the substrate and cladding layer is mainly divided into three stages, and the corrosion mode is intergranular corrosion. Through the experiments, the corrosion characteristics and corrosion mechanism of high strength stainless steel cladding layer prepared by laser cladding are better understood, providing theoretical support for the later repair of parts.