针对高精度光学系统的需求，利用立式Fizeau型干涉仪，结合双频激光测长干涉仪，实现了亚微米量级的高精度曲率半径的测量。为了验证该测量系统的可靠性，分别使用两个参考镜对一系列不同曲率半径的光学零件进行了检测。对产生测量误差的主要因素进行了详细分析，以SiC小球为例，结合不确定度理论，得到测量结果的不确定度约为0.13 μm（假设是正态分布，置信水平约为95%），证明该测量系统满足亚微米测量精度要求。通过三坐标测量机对同一元件的交叉检测，验证了该系统测量结果的准确性。

For the demanding of high precision optical system, a vertical Fizeau type interferometer, combining with dual-frequency laser displacement measuring interferometer, achieve submicron precision measurement of radius of curvature (ROC) in this article. In order to verify the credibility of the measurement system, a series of optical parts with different ROC are measured by two different reference transmission spherical respectively. Take the polished SiC sphere as an example, the main factors causing the measurement errors are analyzed in detail. Combining with the uncertainty theory, the uncertainties of the measurement results of ROC for SiC sphere is about 0.13 μm (a level of confidence of approximately 95% assuming a normal distribution), which demonstrate the measurement system meets the requirement of sub-micron accuracy measurement of ROC. The correctness of the final results measured is verified through the cross measurement of the same component by the coordinate measurement machine.