The size of the sector lock gate in Longzhouyuan ship lock of water diversion project from the Yangtze River to the Hanjiang River is the largest at home and abroad. The water head of the gate bore is also the highest. There are many features which make it is very difficult to analysis the gate by maturity formulas, such as the complexity of 3D spatial structures and stress state, various conditions, the large size of the structure and so on. In order to make known the stress and strain of the gate under various conditions, the finite element analysis model of the large -scale sector lock gate is established by ANSYS finite element method software. The strength, displacement and stability of the sector lock gate are analyzed in this paper. The strength and rigidity of the gate are checked and its safety is assessed. The analysis results could provide a scientific basis to make the design of the lock gate more perfect, and have important value in making the decision for the installation and maintenance of the lock gate.