The crossed roller bearing is a special type of bearing with inner ring splitting and outer ring rotation. Since the divided inner ring or outer ring is fixed to the cross roller collar after being loaded into the roller and the spacer, to prevent separation from each other, the operation is simple when the cross roller collar is installed. Since the rollers are arranged in a cross arrangement, only one set of crossed roller collars can withstand loads in all directions, and the rigidity is increased by 3 to 4 times compared with the conventional model. At the same time, since the inner ring or the outer ring of the crossed roller bearing has a two-divided structure, the bearing clearance can be adjusted, and even if a preload is applied, a high-precision rotational motion can be obtained. Moreover, due to its special structure, it is commonly used as a joint bearing in industrial robots.