The present invention discloses an aluminum alloy material, which is made of raw material of aluminum alloy. The raw material of aluminum alloy consists of the following constituents by percentage of weight: graphene: 0.1%˜1%, carbon nano tube: 1%˜5%, the rest being Al. The aluminum alloy material of the present invention has a good performance of heat dissipation, the thermal conductivity is higher than 200 W/m. Meanwhile, the present invention further provides a method of manufacturing aluminum alloy backboard, in which method, the raw material of aluminum alloy is heated and melted in a heating furnace, afterwards, the raw material of aluminum alloy after melting is formed into an aluminum alloy backboard by die-casting, in this way, the utilization rate of material is increased and the manufacturing cost of the backboard is reduced.