A sealing structure was designed to reduce the leakage of the hydraulic swing vane cylinder.The doorshaped sealing structure has the advantage of selfsealing,which can adjust sealing pressure according to work pressure to complete the adaptive sealing of the sealing face.Based on finite element analysis method,the contact model of the doorshaped sealing structure was established in ANSYS,and the effects of precompression magnitude and work pressure on the contact pressure and oil film thickness of the sealing face were studied.The results show that when the precompression magnitude of the doorshaped sealing structure ranges from 0 to 2 mm,the work pressure ranges from 0 to 3 MPa,the contact pressure of sealing surface is linear with precompression magnitude and work pressure,which reflects the ideal selfsealing of sealing surface.The oil film of the sealing surface is in wedgeshaped distribution,and better carrying capacity and lubricity is realized in the sealing surface,which decreases the frictional force and improves the movement efficiency and stability of the hydraulic swing vane cylinder.