Abstract: To explore the implementation methods of error compensation in CNC systems, an architecture scheme as well as error compensation processes and methods for CNC systems based on domestic platforms are proposed. Research is conducted on the hierarchical-modular overall architecture integrated with non-real-time and real-time domains, the technical scheme of domestic CPUs and the information security scheme of CNC systems for the CNC system architecture respectively. Research is carried out on the methods and processes for geometric error, contour error and thermal error compensation in terms of error compensation. Verification on compensation effects is performed based on the developed GSK domestic CNC system. After geometric error compensation, the accuracy of the four body diagonals of the machining center adopted in the test is significantly improved. After contour error compensation, the roundness error and reverse overshoot at commutation points are effectively reduced. After thermal error compensation, the machining dimensional deviation of machine tools caused by thermal deformation of machine tool spindles is greatly decreased. The research results provide a reference for the development of high-performance domestic CNC systems and their error compensation functions.