为了测量光学元件多层膜膜厚均匀性指标，基于面形检测对多层膜均匀性测量方法进行了研究。分析了均匀性的测量过程以及影响因素，评估了元件面形检测复现性对测量结果的影响，建立了多层膜结构的有限元模型，计算分析膜层内应力对基底面形带来的影响。基于高复现性面形检测装置进行了测量方法的实验验证工作，实验结果表明：元件面形测量口径范围内膜厚分布均匀性优于0.1 nm[均方根(RMS)值]；将测试结果转化为沿径向的轮廓分布结果，与基于反射率计的膜厚检测数据进行了对比，表明两种方法测试数据基本吻合，验证了基于面形检测方法评估光学元件多层膜均匀性的可行性。

In order to evaluate the multilayer thickness uniformity of the optics, the measurement method based on optic figure reproducibility metrology is studied. The process of uniformity measurement and the influence factors are analyzed, and the measurement errors due to the reproducibility metrology are evaluated. The finite element analysis (FEA) model of the multilayer is built and the optic figure error due to the inner stress of the multilayer is calculated. The uniformity measurement is carried out on the high reproducibility metrology device, and the results indicate that the multilayer thickness uniformity of the optic in clear aperture is better than 0.1 nm (root mean square). When the results are transformed to thickness profile along the radial points on the optic and compared with the reflectometry test results it is shown that, the uniformity results based on reproducibility metrology are reliable. The experimental results verify the feasibility and the practicability of the measurement method of the multilayer thickness uniformity.