Abstract: The catenary reinforced method can enhance the crashworthiness of re-entrant honeycomb (RH) by avoiding hollow structural characteristics, strengthening negative Poission’s ratio effect, and utilizing the high load-bearing effectiveness of catenary structure simultaneously. Herein, the sandwich beam with reinforced RH (RRH) is proposed, and its metallic specimens are fabricated to conduct a quasi-static three-point bending experiment. The introduced catenary structure can limit the rotation deformation of inclined cell walls around vertices. By introducing catenary structures, the drop in load-bearing force after initial plastic deformation is reduced from 29.3% to 6.6%. Compared to RH cored beams, the maximum load-bearing force and energy absorption of RRH ones can be improved by 26.7% and 8.9%, respectively. A parametric analysis is conducted to determine that the thicknesses of front facesheet, back facesheet, and core have a significant effect on deformation behavior and energy absorption of RRH cored sandwich beams. The multi-objective optimization is conducted on RRH cored sandwich beams. Compared to the baseline, the maximum load-bearing force and energy absorption of optimized one can be enhanced by 64.9% and 46.9%, respectively. Compared to in-plane and out-of-plane classic honeycomb cored sandwich beams, the proposed reinforced re-entrant honeycomb ones exhibit better anti-impact performance. The research results can provide useful guidance for the reinforcement design of honeycomb cored sandwich beams.