Abstract: Objective In order to improve the effectiveness of negative Poisson's ratio honeycomb structures in the field of naval impact protection, research on the impact resistance of filled straight-walled four-ligament antichiral structures was carried out. MethodsA new straight-walled anti-chiral aluminum alloy honeycomb structure filled with foam concrete is designed. The finite element method is used to model and numerically calculate the filled honeycomb structure, and by comparing its compression collapse mode, stress-strain curve, and specific energy absorption, the enhancement of the impact resistance performance of the honeycomb structural frame by filling the honeycomb structure with foam concrete is explored. Results The results shows that the structure filled with foam concrete changes the form of compression collapse mode, disperses the stress so that the deformation is more homogeneously distributed, and the stress-strain curve changes from the typical form of porous structure to the form of brittle material, and the specific energy absorption of the filled structure can be increased by more than 200% compared with the unfilled structure under the impact of high and low velocities. Conclusion The straight-walled four-ligament anti-chiral structure designed in this paper analyzes the effect of filling plastic material structure with brittle materials on its mechanical properties, which has engineering value in the field of impact protection.