The penetration performance of the double-arrow negative Poisson′s ratio multicellular structure against bullet penetration was studied by numerical simulation method.The penetration behaviors of bullets and the damage forms of the double-arrow negative Poisson′s ratio structure under the three bullet target conditions of top-edge impact,hinge-point impact and side-impact were compared and analyzed.The results show that the negative Poisson′s ratio effect of the double-arrow negative Poisson′s ratio structure is not significant when the bullet impacts the structure at a high velocity.The bullet directly penetrates the structure at topside impact and hinge point impact,the damage of the cell element is small and the anti-intrusion performance of the double-arrow negative Poisson′s ratio multi-cell structure is poor at this time.The bullet does not penetrate the multi-cell structure at side impact,and the damage of the cell element is large;the double-arrow negative Poisson′s ratio structure relies on its double-Poisson′s ratio structure to deflect the bullet at side impact.The double-arrow negative Poisson′s ratio structure relies on its double triangular structure to deflect and roll the bullet during side impact,which significantly increases its penetration resistance.The effect of the change in the angle of incidence of the bullet during topside impact on the intrusion resistance of the double-arrow negative Poisson′s ratio structure was analyzed. It is found that there is a 30° angle of incidence and a 60° angle of incidence.The double-arrow negative Poisson′s ratio multi-cell structure has some resistance to penetration when the bullet is near these two incidence angles.