<p>Honeycomb structures are widely used in buffering, protective systems, and impact-related applications due to their lightweight, high strength, and excellent energy absorption capabilities. However, conventional honeycomb designs often suffer from limited load-bearing capacity, single-stage collapse behavior, and insufficient energy absorption efficiency, making them inadequate for high-performance energy-absorbing systems. To address these limitations, this study proposes a novel Framed Diamond-Star Honeycomb (FDSH) structure with a dual-plateau response. The mechanical performance and energy absorption characteristics of the proposed structure were systematically investigated through quasi-static compression experiments and finite element simulations. The effects of key geometric parameters, including cell angles and wall thickness, were also analyzed. The results show that the FDSH structure exhibits a distinct dual-plateau behavior during compression and achieves significant improvements in specific energy absorption—by approximately 238.18% and 161.97%—compared to traditional star-shaped honeycombs (SSH) and re-entrant hexagonal honeycombs (REH), respectively. Furthermore, parametric studies confirm that geometric parameters have a significant influence on plateau stability and energy absorption performance. </p>