To address the energy absorption and cushioning requirements in low-speed collision scenarios, the work aims to design a novel mechanical metamaterial with quasi-zero stiffness characteristics. Firstly, the geometric structure of the mechanical metamaterial was parametrically modeled, consisting mainly of thin-walled structure and lattice structure. The thin-walled structure was composed of sinusoidal curved beams, and the lattice structure consisted of circular rods that interconnected the thin-walled curved beams into a cohesive unit. To expedite the design cycle of cushioning structures for various application scenarios, a computational method for analyzing the structural mechanical response was proposed. Based on the Euler-Bernoulli beam theory, differential equations for the motion of the thin-walled structure were established. Subsequently, a numerical solution method based on the fourth-order Runge-Kutta method and shooting method was proposed. Finally, based on the superposition principle, the method for predicting mechanical response of the cushioning structure was put forward, and the corresponding linear compensation was carried out. The numerical algorithm presented accurately computed the mechanical response of highly flexible thin-walled structures, thereby reducing the number of design iterations and significantly shortening the design cycle. The quasi-static experimental results demonstrate that the metamaterial configuration proposed in this study exhibits quasi-zero stiffness characteristics and achieves a compression rate exceeding 70%. There is no obvious initial peak of the cushioning structures in the drop hammer impact scenarios, and the response load is suppressed. It shows great potential in the field of cushioning, particularly in impact protection in volume-constrained scenarios.