Airdropped items experience significant mechanical impact upon landing. Consequently, cushioning materials capable of effective impact mitigation and high energy absorption are essential for preserving item integrity. Current protective materials exhibit limited buffering capacity, and enhancing their ability to withstand large deformations while absorbing energy remains a significant challenge. This study introduces a mechanical metamaterial designed to undergo sequential yielding and buckling in a step-wise manner while maintaining load-bearing capacity. Its unit cell incorporates a yielding-buckling element within a lattice framework. Finite element simulations and mechanical testing were performed on the designed structure. The results confirm that the metamaterial achieves the intended sequential buckling behavior, validating the finite element model. Furthermore, the metamaterial simultaneously demonstrates high stiffness and high energy dissipation. Crucially, following the complete collapse of the core yielding-buckling structure, the surrounding lattice progressively crushes to absorb additional energy. This dual-phase mechanism results in exceptional energy dissipation, impact resistance, and superior shock absorption performance. This research presents a novel design paradigm for impact-protective cushioning materials suitable for lightweight protective systems.