Abstract: To solve the problem of difficult maintenance of control systems abroad, the domestically produced Huazhong HNC-818DiM is taken as the research object to upgrade and transform the VMC850 machining center, focusing on key technologies such as control circuit design, PLC program development, and electromechanical integration. Through actual cutting verification, the upgraded machining center has improved its positioning accuracy and repeatability accuracy, fully meeting the requirements of high-speed and high-precision machining. The performance and processing accuracy after the transformation meet the relevant standard requirements. This provides a basis for the digital upgrading and transformation of machine tools with different structures.