Abstract: In order to ensure the accuracy and convergence of the calculation results, the mesh size of the adhesive layer should be less than 1 mm for the failure analysis of composite adhesive layer using the cohesive zone model. However, when the cohesive zone model is used to analysis a large composite material structure in the aircraft, the model will generate millions of finite elements, which will consume numerous computing resources. Based on the research of the influence of the adhesive properties on the adhesive layer failure analysis, by inversion of the adhesive properties with different mesh sizes, the method that can accurately describe the failure behavior of the adhesive layer by changing the parameters of the adhesive layer to adapt to different mesh sizes was proposed. This method was used to simulate the mixed-mode-bending (MMB) model and composite cylindrical shell model with different mesh sizes. The results show that the method proposed can greatly reduce the number of meshes in the model and the calculation scale, and quickly and accurately calculate the damage evolution and failure of the adhesive layer under mixed loading conditions.