The existence form of alloying element Sc and Zr in the micro arc oxidation (MAO) ceramic film on 5B70 Al alloy and their effects on the microstructure, fracture toughness, and tribological properties of the MAO ceramic film was investigated. The findings suggested that the Zr element primarily existed in the form of ZrO2, distributed around the Al2O3 phase. The Sc element remained spherical and dispersed in the form of Al3Sc in the ceramic film. The synergistic effect of ZrO2 and Al3Sc significantly improved the hardness, fracture toughness, and wear resistance of the dense layer in MAO ceramic film on 5B70 Al alloy. This provided theoretical basis and technical support for the development of high-performance MAO composite films on Al alloy surfaces.