Accurately predicting the energy consumption of heavy-duty CNC gear profile milling machine tools is the theoretical basis of energy saving and consumption reduction in the manufacturing process.Therefore,taking the heavy-duty CNC high-speed gear milling machine as the research object,an energy consumption prediction method based on NC program was proposed.The energy consumption characteristics of the energy consuming components of CNC machine tools were analyzed,and the components were classified according to the energy consumption characteristics.The energy consumption model of each component was established,and the calculation method of material removal rate of gear forming milling was proposed.Finally,a gear energy consumption prediction program was developed.Moreover,experiments on two different types of heavy-duty CNC gear profile milling machines show that the prediction accuracy of the method is more than 95%,and the method is feasible.In addition,the feed speed was increased by 10% respectively on the two high-speed gear milling machines in the experiment,the energy savings are 7.52% and 4.25% respectively.The results show that the larger size of the heavy machine tool is,the greater the energy saving potential is.