The machine adopts a fully digital servo speed control system with high speed regulation accuracy and stable performance, and a servo motor as the driving system. The Sida controller is the core of the control system, and the control and data processing software with WINDOWS as the operating interface realizes the screen display of test force, test force peak value, beam displacement, test deformation, and test curve. All test operations can be automatically completed on the computer through a mouse. Good humanized design makes the experimental operation more convenient. Based on the above technologies, this machine can achieve almost perfect closed-loop control of parameters such as test force, deformation, and displacement. It can realize control modes such as constant stress, constant strain, and constant displacement, and can smoothly switch between various control modes.