The structure of Al₂O₃/PMMA overlapping thin films was modeled by finite element simulation method， and the effects of wave structure morphology， period， depth and PMMA thickness on the bending properties of overlapping thin films were studied， respectively. Simulation results showed that the wavy interface structure could greatly improve the bending properties of the overlapping thin film. When the wavy structure had a period of 500~1 500 nm，a depth of 600~1 600 nm and the thickness of PMMA was 6 μm， the overlapping thin film had better bending properties. Under the same conditions， the maximum stress was reduced by more than 70% compared with the overlapping thin film without the interface structure， which could effectively improve the bending performance of the encapsulated thin film. It had guiding significance for the preparation of inorganic/organic overlapping thin films.