以往检测衍射光栅波前时，需自行搭建检测光路，且搭建过程中由于元件较多，造成系统精度难以保证，得到的测量结果不够理想。针对这些问题，本文提出基于 GPITMXP/DX型 ZYGO干涉仪搭建检测光路，并对平面衍射光栅及凹面衍射光栅的衍射波前进行了检测，得到参考光与衍射光的干涉条纹及相关信息，拓展了 ZYGO干涉仪的用途。利用传统的干涉检测法，检测时，干涉仪与标准透镜及反射镜配合使用，标准镜精度接近 λ/40，干涉腔精度为 λ/20。检测得到平面光栅一级衍射光与参考光的干涉条纹及光栅的衍射波前，分析比较了两种检测凹面光栅的方法。与以往检测光栅波前装置相比，本文提出的测量装置精度高、安装简单，不需要搭建专门的波前检测装置，便于重复测量，得到的结果可靠性高。

Former method to detect the wavefront of diffraction grating was based on special system .It is hard to avoid errors caused during setting up optical system because so many devices are used. In this work, the measurement system based on ZYGO GPI. XP/DX interferometer detect the wavefront of plane grating and concave grating, which expanded the applications of ZYGO interferometer. The principle of the system is traditional interference method. ZYGO interferometer is used in concert with standard lens and mirrors as reference device. The precision of reference devices approach λ/40 and the precision of interfere cavity is λ/20. The ±1 order diffraction wavefront and its interference fringe of plane grating are gotten. Two kinds of testing concave grating wavefront were compared. Analysis shows that the new design is simpler and easier to set up compared to past devices.