Abstract: A new design for twoposition threeway pilot solenoid valve is presented, which proposes that two groups of permanent magnets and three groups of control coils construct three permanent magnetic lock circuits and two electromagnetic bias circuits. This proposal not only results in the miniature structure of valve and no power consumption for holding position, but also improves the sealing reliability of valve. Such solenoid valve can be used as the pilot control valve of the main valve of largethrust engine propellant which can meet the  needs of the longterm application in orbit. The feasibility of this design scheme is verified by finite element analysis and productprototype experiment. The verification results show that all performance indices of the new type of pilot solenoid valves achieve the design target.

Key words: major thrust propulsion system, pilot solenoid valve, structure design