The dynamic response of conventional hydraulic priority valve will lag when there is a sudden change in load flow. The response of spools opening and closing is slow because it is limited by ensuring that the pressure stability and the opening response speed are within the designed range. Consequently, the size of the fixed orifice is small so that when working conditions are switched, the closing speed of valves is slow, resulting in a small flow of oil through the orifice, which cannot meet the needs of the system for rapid oil supplementation. In order to solve the above problems, we designed and integrated a speed regulating microvalve in the main spool of the hydraulic priority valve. This microvalve uses the principle of different orifices in different oil flow directions to adjust the opening and closing response speed of the main valve, and achieve slow opening and quick closing of the valve core. According to the dynamic equations of the valve, the designed microvalve is modeled and optimized by simulation. The best matching parameters are determined and the effectiveness of the design is demonstrated. The experimental results show that by reasonably matching the flow area of the fixed orifice, the microvalve can speed up the closing speed of the main valve and replenish the auxiliary circuit oil to the main circuit in a timely manner. Moreover, compared with the traditional main spool with fixed orifice, the closing speed of the microvalve is doubled. When the steering or shifting operation is completed, the speed regulating microvalve can realize that the opening speed of the main valve is slower than the closing speed and reduce the impact of the pressure. This design solves the problem of slow closing speed of the main valve core when switching the priority valve. In addition, it helps the auxiliary pump to quickly supply oil to the main pump and meet large flow demands under different working conditions as well as improve the response speed of the system.