Abstract: As one of the key functional components of CNC machine tools, the electric spindle's working performance directly affects the machining effect of CNC machine tools. The commissioning work before the machining of the electric spindle is of great significance for improving the machining efficiency and performance of the machine tool. This article establishes a digital twin commissioning method for electric spindle for milling scenarios. In response to the problem of reduced reliability of commissioning results caused by changes in operating conditions and sensitive parameters, the system characteristics and operating scenario characteristics are analyzed. A milling scenario model is constructed, and the operating scenario is injected into the twin model. Combining model-based tuning algorithms and manual optimization strategies, a virtual commissioning method driven by digital twins is studied. Taking the speed loop control parameters of the spindle motor as an example, virtual commissioning and optimization of PI parameters were carried out. By comparing experimental test data, it was found that while shortening commissioning time, steady-state error was reduced by 48% and response time was shortened by 13%. This verified the effectiveness of the proposed method and the feasibility of on-site application.