Two-dimensional grating interference measuring device and measuring method

The invention relates to the field of grating measurement, in particular to a two-dimensional grating interference measuring device and method. The two-dimensional grating interference measurement device comprises a grating, a light source, a light splitting assembly, a steering assembly, a first reference reflection assembly, a first measurement reflection assembly, a second reference reflection assembly and a second measurement reflection assembly. The first reference light beam and the second reference light beam are directly reflected to the first detector and the second detector, and the first measurement light beam and the second measurement light beam are obliquely incident to the surface of the grating at a first preset angle and a second preset angle respectively and then are reflected and returned along the same path to form a stable interference signal carrying displacement information. The high-resolution grating is used for obtaining high resolution, meanwhile, the influence of grating surface ty