In order to explore the energy consumption law of CNC machine tools and give full play to the guidance role of energy matching in the selection of key parts of CNC machine tools,the mechanical and electrical energy consumption of ball-screw feed system of CNC machine tools was studied experimentally.The total energy consumption of feed system was divided into electrical power consumption of servo motor and mechanical power consumption (MPC) generated by relative movement of each component.Therefore,the power consumption and efficiency of servo motor were measured and analyzed by designing a new experimental device under the condition of multiple sets of speed and load torque.Furthermore,considering four types of ball-screw pair with different leads,the MPC of each part of the feed system was studied experimentally.The influence of the structure parameters of the ball screw on the power consumption of the system and the relationship between the power consumption of the feed system and the working table speed were clarified.The results show that the working state of the motor has a great influence on its efficiency and the power consumption of the whole feed system;one of the most important factors affecting the power consumption is the motor speed;the power consumption of the system is the balance between the motor efficiency and the MPC.The results can help to select the ball-screw and servo motor reasonably from the angle of energy consumption,and to optimize the feed parameters of the machine tool.