Abstract: Based on the traditional 2D star structure with negative Poisson's ratio, a new 3D star structure with negative Poisson's ratio was designed. The 3D structure has the advantages of lighter weight, higher material utilization and stronger practicability. Through impact experiments and finite element simulations, the deformation behavior mode and mechanical response were deeply studied under different impact speeds, as well as the energy absorption characteristics and impact resistance under different design angles. The results show that the mechanical response of 3D star structure with negative Poisson's ratio can be roughly divided into four stages: stress rising stage, stress plateau stage, platform stress enhancement stage and compaction stage. With the increase of impact speed and design angle, the platform stress and unit mass energy absorption of the model increase. With a design angle of 40°, the model shows a star shape effect in the impact process, which can greatly improve the impact resistance of the structure.