Aiming at the installation deformation of the top seal of reversed tainter valve for high-head ship lock,we apply the method of water stop slice test combining with numerical simulation,and study installation deformation properties of semicircular head top seal,such as the deformation profile,displacement deformation,bulge height and contact width of head,and the distribution law of equivalent stress under different installation loads.The results show that based on prototype material parameters obtained by the mechanical test and theory of contact mechanics calculation,the results of seal deformations obtained by numerical simulation are in good agreement with the results of the scale 1:1 slice test.With the increase of installation torque,the bulge height of the semi-circular head increases approximately linearly,the contact width at the parapet shows a non-linear trend,and the maximum equivalent stress gradient appears at the boundary of seal head contacting with clamp plate and seat plate,which is the most easily damaged part of top seal.