Abstract: Aiming at the serious problem of spherical plain bearing finishing deformation, it is proposed how to design the fixture reasonably in the finishing process and how to accurately calculate the clamping force to reduce the machining deformation of the spherical plain bearing and improve the machining quality of the spherical plain bearing.The basic idea is to design the fixture structure according to the spherical plain bearing structure and processing technology, design the fixture size according to the bearing size, perform static analysis on the fixture, establish a mathematical model of the clamping force according to the static balance principle, verify the fixture through the spherical plain bearing finishing experiment.The reliability of the clamp and the mathematical model of clamping force was verified by the spherical plain bearing finishing experiment, which effectively reduced the deformation caused by the spherical plain bearing finishing process, and obtained the spherical plain bearing with the surface quality meeting the requirements.