The work aims to improve the sealing surface performance of pump valve, thereby expanding its service life and increasing the service reliability of pump valve. Based on the pre-experiment of single-coating, high-power fiber-coupled semiconductor laser was used for preparing multi-channel cobalt-based alloy cladding layer on pump valve material ZG45 plat. By optical morphology (OM), scanning electron microscope (SEM), X-ray diffractometer (XRD), energy dispersive spectroscopy (EDS), microhardness tester, salt spray corrosion chamber and other experimental test instruments, the morphological characteristics, composition, microhardness and corrosion behavior of the cladding layer were analyzed to determine the process parameters and properties of the multi-channel cobalt-based coating. The multi-channel cobalt-based cladding layer had feasible process parameters, dense structure and good metallurgical bonding with the substrate. The coating microstructure was mainly composed of columnar crystal, cell crystal, columnar dendrites and inter-column eutectic structure. The main phases of the cladding layer were γ-Co and Cr23C6. The dendrite center was mainly formed by Co and Fe elements, and the content decreased from the dendrite center to the surrounding area. The interdendritic mainly consisted of Cr, C and W elements, which were evenly distributed in the interdendritic. The average microhardness of the coating was 586.5HV0.3 more than 2.8 times higher than that of substrate and the microhardness of cladding layer increased with the decrease of dilution rate. The salt spray resistance of cladding layer was significantly improved. The surface laser cladding technology based on cobalt-based alloy can effectively improve its hardness and corrosion resistance, and can be used to enhance the performance of sealing surface of pump valve.