In order to solve the problems of complicated operation, low automation, failure of electronic components and frequent maintenance of EJ II-100 Lever Force Standard Machine, the electrical circuit and control system were upgraded while the mechanical structure of EJ II-100 Lever Force Standard Machine was inspected and repaired. The current mainstream PLC control mode was used to replace the traditional MCU control, and the function and technology of the transformed Force Standard Machine were also improved. The test results show that the working stability and automation control degree of the force standard machine are improved. The experiment proves that the functions and technical indexes of the improved force standard machine meet the design objectives and the requirements of the national verification regulations.