When the vane seal slides on the contact surface of the end seal of a hydraulic rotary vane actuator (RVA), this surface undergoes elastic deformation, and even seal failure may occur through the combined action of the normal contact pressure and tangential force. In this article, a model of the elastic deformation of the contact surface of the end seal is established, and factors influencing elastic deformation are studied. The results show that deformation of the contact surface of the end seal in the x– and y–direction increases with an increase in the pre-tightening force. However, deformation of the contact surface of the end seal in the x– and y–direction is reduced as the vane-seal radius and the end seal elastic modulus increase.