A Polyethyleneimine functionalized graphene oxide (GO) hybrid epoxy resin composite coating was prepared by electrophoretic deposition technology to construct the parallel-aligned GO in the coating toward high-performance friction/wear resistance. Results from experiments and molecular dynamics clarify that the addition of parallel-aligned GO into epoxy coating can significantly reduce the wear rate up to 71%. Meanwhile, its Young's modulus, shear modulus and bulk modulus were strengthened by 70%, 36%, and 65%, respectively, with pure epoxy coating as a comparison. The improvement in composite coating's mechanical and tribological properties is attributed to the strong interaction between the functionalized-GO and the matrix, as well as the efficient barrier effect from the parallel arrangement of functionalized-GO. The parallel-aligned GO can effectively prevent the coating from cracking and flaking, improve mechanical qualities and produce the tribo-protective film, resulting in high load-carrying and wear resistance capabilities. Our work provides effective guidance for designing nanocomposites with long-term durability.