Based on the density functional theory of first-principles, diffusion migration behavior of alloy atoms in the aluminum matrix and the graphene/aluminum interface are investigated in this paper. By comparing the migration barriers of aluminum atoms at the aluminum matrix and at the graphene/aluminum interface, it is found that aluminum atoms prefer to migrate toward the interface to provide conditions for the formation of the brittle phase Al₄C₃. Diffusion migration behaviors of 41 alloying atoms at the aluminum matrix and graphene/aluminum interface are calculated, and a group of alloying elements (Sc, Cu, Si, Ni, etc.) that tend to aggregate at the interface are selected. It is also found that Si, Cu, Ni, and Co are more likely to migrate to the interface than Al atoms. Finally, the migration behavior of alloying atoms at the graphene/aluminum interface with a carbon atom vacancy defect are explored, compared to the perfect interface, the migration energy of most alloying atoms at the graphene/aluminum interface with a carbon atom vacancy defect does not vary much, while Sc and B atoms prefer the graphene/aluminum interface with vacancy defect. The results of the theoretical study are expected to provide a theoretical basis for the experimental design of future high-performance graphene/aluminum composites.