为了验证离子束修正超高陡度镜面的能力，对采用五轴离子束加工超高陡度镜面的问题进行了分析研究和加工实验。根据现有检测条件制定了实验方案并对面形数据进行了处理；对超过机床五轴加工摆轴行程区域的驻留时间进行了补偿；建立了离子束五轴加工后置处理算法，根据该算法编制了数控程序生成软件，并通过实验验证了生成的数控程序的正确性；最后进行了超高陡度镜面的五轴离轴加工实验，经过5 轮迭代加工后，元件面形由初始的峰谷(PV)值为57.983 nm、均方根(RMS)值为9.406 nm，收敛PV 值为11.616 nm、RMS 值为1.306 nm，总收敛比达到7.20。实验结果表明：采用五轴离子束加工超高陡度镜面的方案可行，并且获得了较高的收敛效率和加工精度，同时验证了离子束离轴镜加工的可行性。

In order to verify the machining capability of ultra-gradient mirror figuring by ion beam, the figuring of ultra-gradient mirror by 5-axis ion beam is investigated. First, based on the existence measure condition, the experiment scheme is presented and the surface figure date is processed. The dwell time of the area exceed the machine range is compensated. Then the post processing for 5-axis ion beam figuring machine is established, the numerical control generate software is programed based on the post processing, and the correctness of the numerical control program is verified through experiment. Finally, the off-axis figuring experiment of ultra-gradient mirror by 5-axis ion beam is carried out, and through five iterations, the surface figure is improved from initial condition: the peak valley (PV) value is 57.983 nm, the root mean square (RMS) value is 9.406 nm to final condition: PV value is 11.616 nm, RMS value is 1.306 nm. Convergence ratio reaches 7.20. The results indicate that ultra-gradient sphere mirror can be figured by 5-axis ion beam figuring machine to achieve high efficiency and precision, and the figuring of off-axis mirror by ion beam figuring is verified at the same time.