“The flexible bridge displacement amplification mechanism has attracted much attention in the field of precision engineering. The latest research has conducted nonlinear modeling and optimization for its design analysis, achieving semi analytical modeling of input-output relationships through energy method, finite element method, and numerical fitting, and predicting nonlinear results more quickly. At the same time, a comprehensive optimization strategy for mechanism size and thickness was proposed, aiming to maximize output displacement and suppress geometric nonlinearity. ANSYS simulation shows that the modeling error is within 5%, and the optimization results are effective. This study has reference value for nonlinear prediction and optimization of other complex compliant mechanisms.”