Based on a high speed electromagnetism valve and a two side throttle slide valve, a digital shift pressure regulation valve was designed. The electromagnetism valve was driven directly by the digital signal of electricity control system, the automatic shifting and the pressure’s real time regulation of shift clutch was achieved. The principle of the electricity control system was stated, based on the characteristic of the electromagnetism valve, the drive circuit was designed. The digital electro hydraulic automatic control system was installed on the heavy vehicle with hydro mechanical transmission, and tested. According to the test data of shift process, the control strategy is analyzed, and the validity and feasibility of the control system is proved.