Abstract: Multistable structures are a type of nonlinear systems, they have multiple equilibrium states. These structures show great application potential in areas like energy dissipation, impact protection, and vibration control. This paper presents a bistable structure based on the buckling behavior of flexible rods. A corresponding mechanical analytical model is built. Key design parameters are defined, which are the stiffness ratio k and the initial angle θ₀. By deeply analyzing how parameter changes affect the structural response, the boundaries between three response modes are identified. These modes are superplasticity, superelasticity, and monostability. Design guidelines for engineering practice are provided. To check the accuracy of the theoretical model, finite element numerical simulations are performed. The computational results confirm the model's good reliability. This study offers a systematic theoretical basis, and a methodological support, for the parametric design and for the engineering application of multistable structures.