In order to change the current situation of limited application of measurement methods and compensation technologies for the spatial error of CNC machine tools in domestic,and research methods for improving the spatial accuracy of CNC machine tools,the 21 geometric errors of the translation axis of CNC machine tools and the spatial errors testing principle of the laser tracker were introduced,and the steps and methods of measuring and identifying machine tool spatial errors were described.The spatial error test was carried out on the bridge type five axis machining center,the test results were given,and the error compensation file was generated.The error compensation was carried out through the Siemens VCS function.21 errors before and after compensation were compared and analyzed,and the reasons for the difference of data before and after compensation were analyzed.The actual effect of spatial errors measurement and compensation was verified by measuring the diagonal of the machine tool space body.After compensation,the error is reduced to 11.2%.The application of this technology can greatly improve the space accuracy of the machine tool.