The high temperature melting and sintering of Cu powder will seriously limit the coverage of graphene on the surface of Cu powder during the in-situgeneration of graphene. To solve this problem, MgO was added as a dispersant preventing Cu powders from bonding together due to surface melting during the chemical vapor deposition. The results show that the graphene/Cu powder prepared by this method had higher coverage, and the graphene/Cu composite sintered had better mechanical and anti-corrosion properties. It was attributed to the grain refinement strengthening effect and dislocation strengthening effect by the introduction of graphene. Meanwhile, graphene reduced the coverage of CuCl during Cl−corrosion. Therefore, this method provided a new idea for the preparation of high strength and high corrosion-resistant graphene/Cu composites.