Abstract: The graphite/Cu composites have excellent tribological properties and corrosion resistance so which show a broad application prospect in the field of high-speed railway. Due to the non-wetting of graphite with Cu and the low interfacial bonding strength of graphite/Cu composites, the graphite easily peels off under the high load and it could result in the poor performance of the composites. The interface of graphite/Cu composite could be modified by the surface treatment of the graphite with Sn element, which could not only improve the interfacial bonding but also improve the mechanical properties, so that the composites could meet the service conditions. The results show that there is no new phase formation in the microstructure of Sn coated graphite/Cu composites by the interfacial modification. A strong interdiffusion occurs at the interface of the Sn coated graphite/Cu composites and the interfacial bonding changes from mechanical bonding to diffusion bonding. The mechanical properties of the Sn coated graphite/Cu composites are significantly improved. The hardness and flexural strength increase 80.43% and 246.74%, respectively. When the graphite content is 6wt%, the hardness is (83.61±4.33) HV, and the bending strength is (410.41±20.52) MPa, which could meet the service requirements in the future.