Abstract: In this paper, a relatively authentic three-dimensional finite element model of C-ring is established. The sealing behavior of C-ring is simulated by ANSYS while the coupling of elastoplasticity and contact is taken into consideration. With the numerical simulation, the compression-springback characteristic curve of C-ring is obtained. As the characteristic curves are coincident with test results, the validity of the numerical simulation method is confirmed. In the compression state, the stress in the spring is higher at the 0°, 90°,180° and 270° regions. In the springback state, the linings will warp to make the gap of linings be wider. The interaction of each part of C-ring will influence the sealing behavior obviously.