Abstract: When using continuous uniform medium model to characterize the plastic deformation in layered aluminum film mechanical engraving process, it is difficult to accurately reveal the influence of micro-structure of aluminum film on stress transfer, which directly hinders the acquisition of precision control groove forming technology. Firstly, the micro-structure of aluminum film of grating blank was obtained by SEM, and a two-phase grain model reflecting grain boundary characteristics was established based on mixing ratio theory. Secondly, the mechanical properties of the aluminum film with layered structure were obtained by nano indentation and scratch experiments. Finally, the mechanical engraving process of grating was simulated and analyzed by ABAQUS software. The results show that: The grain boundary near the groove stores the compressive stress after deformation, which hinders the release of tensile stress in grain. And springback in the simulation is consistent with the scratch data, the error is reduced by halfcompared with the traditional model, so the two-phase grain model can reveal the loading deformation law of the aluminum film with layered structure.