Based on the multibody system theory combined with the homogeneous coordinate transformation principle, taking example for i5T52 CNC lathe, the comprised parts and topological structure on this lathe were analyzed. Its geometric error model was established through Matlab software programming. Through highspeed computing in computer, the error model was analyzed, and its results were displayed in the form of statistical figure, so as to easily find law of errors distribution and interactive law of errors. Correct model was well verified by comparing analysis results between modeling of machine tool errors and measured machining errors in actual machining of stick materials. In the following actual machining, analyzed data in errors modeling are applied in error compensation, which can effectively improve the precision of the machine tool.