点衍射干涉仪是现代超高精度面形测量中常用干涉仪,其参考波由一定尺寸针孔衍射产生,因此摆脱了参考元件面形误差对测量精度的限制,使纳米及纳米级以下精度测量成为可能。点衍射干涉仪由于其结构特点,主要的系统误差来源于针孔衍射波与理想球面波的偏差。设计了一种新的点衍射干涉仪系统误差标定结构,降低了对准难度。同时提出了利用干涉图信息计算CCD位置,去除几何结构慧差的方法。搭建了基于双孔干涉的系统误差标定系统,在针孔直径为3μm时,系统误差为0.009λ。 Point diffraction interferometer is commonly used in modern ultra-high precision surface measurement interferometer, the reference wave diffraction by a certain size pinhole generated, so get rid of the reference element surface shape error of the measurement accuracy of the limit, so that the following nano and nano-precision measurement become possible. Point diffraction interferometer due to its structural characteristics, the main system error comes from the pinhole diffraction wave and ideal spherical wave deviation. A new error calibration structure of point diffraction interferometer system is designed, which reduces the difficulty of alignment. At the same time, a method of calculating CCD position using interferogram information and removing coma aberration of geometric structure is proposed. The systematic error calibration system based on two-hole interference is built. The system error is 0.009λ when the pinhole diameter is 3μm.