The measurement and compensation of volumetric error is an important means to improve the machining accuracy of machine tools. A measurement method based on a laser Doppler displacement meter is used to identify the geometric error elements of the machine tool. Then, based on the theory of homogeneous coordinate transformation, the volumetric error model of the vertical machining center is established. And use offline modification of G code to implement machine tool volumetric error compensation. Compared with the laser interferometer multiline method, the method of sequential step diagonal is simpler and faster, and 12 key geometric errors can be quickly obtained through 4 tests. The results of error test and compensation show that the overall accuracy level of machining center has been greatly improved, and the body diagonal error has been reduced to 32.5%.