The selflocking valve is restricted by pressure and flow,so it is difficult to meet the application requirements of highpressure and largeflow hydraulic and pneumatic systems.Therefore,a kind of high pressure and large flow pilot selflocking valve with compact structure,high reliability and simple operation was proposed.The high pressure selflocking valve was used as the pilot stage and the pressure differential was used to drive the main valve;the valve was cleaner and more energy efficient by using an internal overflow structure to make the valve no fluid overflow.The structure principle of the selflocking valve was discussed,and the key electromagnetic part and flow field of the valve were simulated,by which the effectiveness of the scheme was proved.