To improve the bonding strength between carbon/carbon composites (CC) and Mg-CaP (MCP) coating, SiC nanowire (SiCnw)-carbon nanotube (CNT) hybrid reinforcement is synthesized on CC substrate to reinforce MCP coating. SiCnw-CNT hybrid reinforcement was prepared by chemical vapor deposition and injection chemical vapor deposition method. MCP coating was prepared by electrochemical deposition method. The morphology, microstructure, and phase composition of the hybrid reinforcement were characterized. The bonding strength and simulated body fluid immersion (SBF) response of SiCnw-CNT reinforced MCP coating were investigated. Results indicated that SiCnw-CNT hybrid reinforcement formed a porous three-dimensional network structure. The surface of SiCnw-CNT hybrid reinforcement contained abundant oxygen-containing functional groups. The MCP coating was consisted of HA phase and DCPD phase and exhibited a flake-like morphology. The deposition mechanism of the coating was explained. The bonding strength of SiCnw-CNT reinforced MCP coating was 39.30% higher than that of SiCnw enhanced MCP coating and was 142.44% higher than that of the pure MCP coating. In SBF immersion test, a dense apatite layer could be formed on the surface of the SiCnw-CNT reinforced MCP coating after 14 days of immersion. The SiCnw-CNT reinforced MCP coating may be potentially applied in the field of bone tissue engineering.