The work aims to study the static cushioning property of irregular cushions to pinpoint their difference from ordinary cushions in property. With expanded polyethylene (EPE) as the test material, it was cut into a prismoid cushion. The universal compression tester was used to carry out the static compression test on the samples of the same equivalent area but different side dip angles. Stress-strain curves, energy absorption curves and cushioning coefficient curves were plotted. Comparisons on the data between the above-mentioned curves and the regular hexahedron cushions were made. The rigidity of the irregular cushions was smaller than that of regular cushions. The rigidity became smaller with the decrease in the side dip angle. The energy absorption of the irregular cushions approached that of the regular cushions at the same stress level. However, the energy absorption of irregular cushions was smaller than that of the regular cushions at the same strain level. The cushioning coefficient of the irregular cushions was smaller than that of the regular cushions when the load was small. The difference was not significant with the increase of the stress. There is a significant difference in the static cushioning property between the irregular and regular cushions. Therefore, to avoid excessive packaging or insufficient packaging, considerations should be carefully taken for the design of cushioning package according to the specific circumstances.