Abstract: In order to study the stress distribution and the ultimate strength of the hook of uniform cross section subjected to load, a stress distribution model of the hook is established as a curved beam. The numerical method of ANSYS is used to test the theoretical solution of the hook, which also helps to identify the dangerous section. Three failure principles are established based on the displacement, the limit of elasticity and the principle of plastic design, providing a theoretical basis for the factory to produce hooks of different sizes under different ultimate loads.