Ni-based WC/Cr3C2 composite coating is produced on 1045 steel substrates by high-power CO2 laser. The chemical composition, phase composition, microstructures and corrosion resistance of the cladding layer are analyzed respectively by electron probe microanalyzer (EPMA), X-ray diffractometer (XRD), scanning electron microscope (SEM) and M352 electrochemical measurement system. The results show that the surface of the Ni-based WC/Cr3C2 cladding layer is bright and crack free, and the wettability and slag detachability are excellent. The cladding layer is mainly composed of Cr2Ni3, γ-(Fe, Ni), Ni17W3, Fe0.64Ni0.36, WC, Cr7C3 and CrSi2. Dentrite is highly developed on the bottom of the cladding layer, with abundant Fe elements distributed in the dendritic and interdendritic grains. The central zone are plenty of long strip shape Cr7C3 and some chrysanthemum-like CrSi2 distributed on the γ-(Fe, Ni) base. The microstructures of the top zone are similar to the central zone′s, but the grains are finer and denser. The corrosion potential and corrosion current density of Ni-based WC/Cr3C2 cladding layer are respectively -359.9 mV and 2.75 μA/cm2, which indicates that the corrosion resistance of the cladding layer is improved obviously compared with Ni-based WC cladding layer.