The work aims to study the influence of density of polypropylene material on its impact performance, with the polypropylene material as the study object. The dynamic crushing experiment was conducted on the polypropylene materials of four different densities to analyze the contact force, displacement and strain, as well as the change of absorbed energy and specific energy absorption, thus studying the dynamic crushing behavior of polypropylene materials of different densities under dynamic conditions. With the increasing impact energy, the maximum contact force, maximum displacement, maximum strain and specific energy absorption increased gradually for the given density. When the impact energy was fixed, the maximum contact force increased with the increase of density, while the maximum displacement, maximum strain and specific energy absorption decreased with the increasing density. For the weight reduction and cost saving, it is possible to use the polypropylene material with low densities when selecting the cushioning materials within a safe range.