In the design of express packaging, the buffering effect of corrugated board and expanded polyethylene (EPE) composite materials should be considered comprehensively to reduce the amount of buffer materials. With EPE, three-layer corrugated board, and five-layer corrugated board commonly used in express packaging as the research object, the experiments were designed according to GB/T 8167—2008. The maximum acceleration-static stress curve of the materials were calculated and fitted. The results showed that the thicker the EPE material, the better its buffering performance. Three groups of materials of EPE, three-layer corrugated board/EPE, five-layer corrugated board/EPE were fitted with hyperbolic function, and the fitting degree was greater than 95%. The fitting effect was good. Under the same static stress, dynamic cushioning performance:five-layer corrugated board/EPE>three-layer corrugated board/EPE>EPE. The fitted function can be used for design of express packaging. The experiment result provides a basis for the reduction design of express packaging.