The slewing bearing is a large-sized bearing that can withstand a large load such as large axial load, radial load and overturning moment, and combines various functions such as support, rotation, transmission and fixing. Under normal circumstances, the slewing bearing itself has mounting holes, lubricating oil and sealing device, which can meet the different needs of various types of mainframes working under various working conditions; on the other hand, the slewing bearing itself has a compact structure and guide rotation. Convenient, easy to install and easy to maintain, it is widely used in large-scale rotary devices such as lifting and transporting machinery, mining machines, construction machinery, port machinery, wind power, medical equipment, radar and missile launchers. The slewing bearing is a large-sized bearing that can withstand a large load such as large axial load, radial load and overturning moment, and combines various functions such as support, rotation, transmission and fixing.