Abstract: In order to greatly improve the machining accuracy of the vertical machining center, so as to meet the high-precision requirements of contemporary CNC machine tools, for the three motion axes of the vertical machining center, an in-depth analysis of the geometric errors of the axial motion space is proposed, and the motion axis can be effectively identified to identify the six geometric errors in the motion space, the six spatial geometric error identification models are established, and the verticality errors of the associated axis linkage are effectively analyzed, and the verticality error identification analytical model is established. At the same time, for three independent motions based on the axial positioning error characteristics of the shaft, a highly applicable error compensation method is proposed, an error compensation model is established and the compensation implementation plan is refined. Experiments prove that the study of spatial geometric error identification analysis and positioning compensation methods can greatly improve the positioning accuracy of vertical machining centers.