本文讨论了用不透明的衍射光栅代替多面体的反射面对度盘进行检验的原理、方法以及应用该方法时所必须满足的条件。该方法是将不透明的衍射光栅固定在多面体的表面上,使光栅平面和光栅槽平行于多面体的轴,以单色光照明,使光栅引起衍射,产生多级衍射光束,这同增加反射面的效果是相同的。该测量方法的优点在于,使用一个相应的衍射光栅的多面体能测量很小的角度。 In this paper, we discuss the principle and method of inspecting the reflection plate with opaque diffraction grating instead of polyhedron and the conditions that must be satisfied when using this method. The method is to fix the opaque diffraction grating on the surface of the polyhedron so that the grating plane and the grating groove are parallel to the axis of the polyhedron and illuminate with monochromatic light to make the grating diffract and generate multi-order diffracted beams, The effect is the same. The advantage of this measurement method is that polyhedrons using a corresponding diffraction grating can measure very small angles.