In order to improve the hydraulic pressure of aircraft to 28 MPa, a jetpipe electrohydraulic pressure servo valve with rated pressure of 28 MPa was designed by a research institute. The pressure gain of the valve was a oneway positive gain and had a force feedback on the structure.Based on the physical structure of the valve, the corresponding mathematical model was established, and the dynamic performance of the 28 MPa pressure servo valve was analyzed. The feasibility of the project was proved by theory. At the same time, according to the dynamic analysis results of the valve, the relevant methods to improve the frequency response of the valve were introduced.