Abstract: Taking Co06 Co-based alloy powder as cladding material, laser remanufacturing technology was used to prepare cladding layer on the excessive wear surface of 30CrSiMoVA steel brake disc for high-speed train. The microstructure, hardness, friction and wear properties of the cladding layer were studied, and the wear mechanism was discussed. The results show that the cladding layer prepared on the excessive wear surface of the brake disc was well combined with the substrate, and the Co element diffused at the interface between the cladding layer and the substrate. The average microhardness of the cladding layer was 548 HV, which was 2.3 times that of the substrate. The average friction coefficient of brake disc after laser remanufacturing was 0.485, which was smaller than that of the original brake disc; the wear mechanism of both was fatigue wear and abrasive wear, but the wear degree of brake disc after laser remanufacturing was significantly slight. The wear volume of brake disc after laser remanufacturing was 7.709 mm³,and was smaller than 10.011 mm³ of original brake disc, indicating that the wear resistance was improved.