A new type of digital hydraulic transformer was designed by using several basic components such as gear pump/motor units and control valve groups. The digital hydraulic transformer combined the discrete, simple and easy to control characteristics of digital components, and was grouped by a plurality of gear pump/motor units with different displacements. Rigid connection was made between the drive gear shaft of each gear pump/motor to achieve the purpose of synchronous rotation. Solenoid switch valves were installed respectively through the integrated valve blocks at the inlet and outlet of each gear pump/motor unit, throttle valve was installed in the output port of the digital hydraulic transformer to simulate the load of the whole hydraulic system, the low pressure ports of the inlet and outlet control valve groups were connected together to access the oil tank. According to the binary digital control by changing the power on/off state of the inlet and outlet valve groups, the digital hydraulic transformer can realize the change of output flow due to the existence of low pressure oil port, and then realized the change of output pressure. The AMESim simulation software was used to analyze the pressure change process of the digital hydraulic transformer, and the digital hydraulic transformer was verified by using the test platform. The results showed that the proposed digital hydraulic transformer can change the output pressure by digital control, and the feasibility of the pressure change principle was determined. 