Optimizing the processing conditions is one of the effective ways to reduce energy consumption of machine tools. By analyzing the energy consumption components of machine tool processing, an energy consumption optimization method based on virtual machine tool was proposed. Based on the dynamics of the machine tool feed drive system, the virtual machine tool was modeled. On the model of virtual machine tool, by modifying the cost function or component model, considering the change of optimization objective or machine tool design, genetic algorithm was used to optimize the processing conditions in order to estimate the energy consumption in the processing process, the optimal processing conditions were obtained, and the optimal processing conditions were imported into the real machine tool to reduce energy consumption in the processing process. To verify the validity of this method, a machine tool test bench with energy consumption monitoring system was established. The coincidence between virtual machine tool and real machine tool processing was tested on the machine tool test bench. At the same time, the validity of the optimal processing conditions obtained by virtual machine tool was tested. The test results show that the virtual machine tool processing is in good agreement with the real machine tool; the energy consumption of the machine tool is reduced by 2271% when the optimal processing conditions are introduced into the real machine tool, compared with the machine tool without optimization.