The nano tungsten carbide and cobalt-based alloy powder containing ZrO2 and SiO2 were coated on the surface of the test ball valve substrate by using a 5 kW fiber laser. The microstructure of the cladding layer was observed and analyzed, and the microhardness and friction performance of the strengthened layer was tested. The test results show that the microstructure of 50% mass fraction cobalt, 40% mass fraction nano tungsten carbide and 10% mass fraction metal oxide sample is uniform and compact without cracks and pores. The average thickness of the laser cladding strengthening layer is 1.4 mm, and a metallurgical bond is formed between the reinforcing layer and the substrate. There are network-like and point-like distribution strengthening phases in the strengthening layer. The network-like strengthening phase is mainly WC, and the point-like distribution strengthening phase between the networks is mainly metal oxides ZrO2 and SiO2. The average microhardness of the surface layer of the strengthening layer is 65 HV, which is more than 110% higher than that of the matrix material. At 20 ℃ and 300 ℃, the sample wear amount decreased by 75.3% and 68.2% compared with the substrate. Among them, the network-like WC strengthening phase enhances the hardness of the coating. The metal oxide strengthening phase dispersed between the networks enhances the wettability of the alloy powder and reduces the generation of pores and inclusions. The main wear mechanism of the strengthening layer is a small amount of adhesive wear, and the strengthening layer is beneficial to improve the wear resistance of the ball valve and the service life in actual working conditions.