Abstract: A hydraulic valve is a control element that controls the pressure, flow, and direction of the fluid flow. At present, the main principle of the flow control valve in the hydraulic field is to change the throttling area and then change the flow using the spool movement. Based on the principle of a pilot relief valve, a hydraulic valve with a coaxial pilot spool and main spool was designed. The design method of flow performance control for the hydraulic valve based on CFD simulation was proposed, and different structures of the main spool were compared. A mathematical model based on the structure of the pilot electro-hydraulic proportional valve was established and simulated with MATLAB. In order to verify the dynamic and static flow performance of the valve, a MATLAB model was established to determine the area-displacement characteristics of the valve core to achieve proportional flow control. Experiments were carried out on a test bench to verify the static and dynamic flow performance. The results show that the valve core with a rectangular hollow buffer head has good small flow ratio characteristics. The curve linearity coefficient between voltage and flow of the electro-hydraulic proportional valve was 0.983, the dynamic step effect overshoot of flow was 7%, and the adjustment time was 0.02 s.