Abstract: The working process of the water ring vacuum pump needs to adapt to a variety of complex working conditions. The mechanical properties of key components and the reliability of motion pairs have an important impact on the overall work of the water ring vacuum pump. In this paper, ANSYS is used to analyze the key components of the water ring vacuum pump, and the displacement and stress nephograms of the components are obtained. The stress analysis of the key kinematic pair is carried out, and the forces and moments in all directions are obtained. The results show that the stress distribution of the pump body, pump cover and distribution plate is uniform, and less than the yield limit of the material, the deformation amount is less than the allowable deformation amount, and the strength and stiffness are sufficient; the action force and action moment of the kinematic pair are less than the maximum bearing strength, and the connection mode is reliable.