Abstract: WC-Co particle reinforced NiCrBSi composite coating (NiCrBSi/WC-Co composite coating) was prepared on the surface of 42CrMo alloy steel substrate by coaxial powder feeding laser cladding technique. The phase composition, microstructure, microhardness and wear resistance of the composite coating were investigated. The results show that the primary phases of the composite coating were composed of γ-Ni solid solution, WC, FeNi₃, B₂Co₃, CoC_x, FeCr_0.29Ni_0.16C_0.06, W₃C and Co₃W₃C₆. There were disoriented fine dendrite crystals at the upper area of the composite coating, massive columnar dendrite crystals in the middle area and cellular crystal which grew perpendicular to the interface at the bottom area. A good metallurgical bonding between coating and substrate was obtained. The average microhardness of the composite coating surface were 810 HV, which was much higher than that of the substrate (270 HV); the wear mass loss was 0.3 mg, which was much lower than that of the substrate (1.9 mg); the wear mechanism was abrasive wear. The composite coating could significantly improve the wear resistance of 42CrMo steel substrate.