在大口径望远镜主镜液压支撑形式中，液压缸需要一种简单可靠、不需要润滑维护的精密导向机构，而且可以输出较大行程范围(毫米级)。设计了一种柔性金属膜片机构用于液压缸的径向定位导向。建立了金属膜片机构有限元模型，采用几何非线性算法，研究分析了不同拓扑结构对金属膜片柔度的影响，通过不同拓扑结构金属膜片的性能分析对比可知，V型膜片能够很好地克服应力刚化，保证柔度的稳定性；以柔度为优化目标，对金属膜片V型的位置尺寸和形状尺寸进行了优化设计，金属膜片在导向方向上的柔度提高了14.2%；搭建了柔性金属膜片机构柔度测试平台，验证了仿真计算结果。结合实验和仿真结果可知：V型柔性金属膜片具有良好的定位导向性能，对用于液压支撑的液压缸和主动光学的微位移促动器的导向机构的设计具有指导意义。

For large-aperture primary mirror hydraulic support system, a simple and reliable precision guiding mechanism is needed to give a larger stroke range(mm) for cylinders, which did not require lubrication and maintenance. In this paper, a flexible metal membrane was designed for the cylinder guiding and radial positioning. With the method of finite elements and nonlinear geometry algorithms adopted, an analysis was carried on the flexible membrane with different topologies, it was shown that V-shape metal membrane could well overcome stress stiffening and maintain the stability of flexibility; with flexibility as the optimization target, optimize the V-shape position and geometry dimensions of membrane V-shape, and the guiding flexibility of metal membrane was improved by 14.2%; established the experimental platform, did experiments and verify the simulation results. According to the experiment and simulation results, the V-shape membrane is found not only having a good flexibility in the vertical surface direction, but also ensuring the stability of flexibility by avoiding stress stiffening. These founds give a certain guidance in the design and application of the guiding mechanism for hydraulic support cylinders and active micro-displacement actuator.