In order to solve the problem of relief valve performance deterioration caused by plastic deformation and fracture of the traditional mechanical spring,a compound magnetic and electric spring structure was designed and applied to the pressure regulating spring of direct action relief valve to improve the response speed of direct action relief valve,and achieve the electric control spring force.The magnetic characteristics of the compound magnetic-electric spring were analyzed theoretically,and Maxwell software was used to simulate the magnetic characteristics of the compound magnetic-electric spring.The dynamic characteristics of the mechanical spring direct action relief valve and the compound magnetic and electric spring direct action relief valve were simulated by AMESim software.The magnetic characteristics of the compound magnetic-electric spring and the dynamic characteristics of the relief valve were tested experimentally.The results show that the design of compound magnetic-electric spring is reasonable,the dynamic response of the compound magnetic and electric spring direct action relief valve is better than that of the existing mechanical spring direct action relief valve.