The compliance features of flexure hinges were analyzed to design and optimize the flexible amplification mechanisms. A new general structural parameter called compliance ratio λ was proposed. The sensitivities of main type of output displacement of the flexure hinges with different compliance ratios λ were analyzed, and the effect laws of compliance features on the commonly used flexure hinges were also discussed in detail. Then, by taking the compliance ratio λ as the basic parameter, the theoretical calculation method of the amplification ratio of a two-stage lever-type flexure hinge mechanism was proposed in considering the offset of the flexure hinges rotation. The optimization design of the flexible amplification mechanism was studied on the basis of the characteristics of the compliance ratio λ. The finite element simulation and the experiment were performed. The results show that the amplification ratio of the optimized flexible amplification mechanism is larger than that of the flexible mechanism before optimization, and the increases of the simulation and the experiment are 0.234 and 0.23, respectively. These results demonstrate that to optimize the flexible amplification mechanism based on the compliance ratio λ of flexure hinges improves the amplification ratio and the working range significantly, and enhances the accuracy of movement and positioning of the amplification mechanism.