The work aims to study the difference in static cushioning property of prism cushions (EPS) with different structural parameters when their contact area is the same and the volume is the same. With expanded polystyrene (EPS) as the test material, the static compression test was carried out on ten groups of samples with the same contact area, the same volume, different thickness and inclination by universal pressure tester. The stress-strain curves, strain energy-strain curves, strain energy-stress curves and cushioning coefficient-static stress curves of ten groups of different structural parameters were obtained. As the inclination of the bevel increased, the cushion stiffness increased gradually, and the energy absorption increased. When the inclination was greater than or equal to 70°, the cushioning property was basically the same. Under the condition that the cushion was subject to the same large impact strength, the prism cushion of 80° inclination had the best cushioning property and the largest strain energy, and the deformation and stress generated by the cushion were smaller than those of the ordinary hexahedral cushion. In the packaging design process, 80° inclination can be set on the side of the contact surface. Based on the packaging with such structural design, the product is safer and the thickness of the contact part can be reduced by 25.12%, realizing cost decreasing and benefit increasing.