In order to solve the problems of bearing abnormal noise and high noise caused by the ball loading plug of thrust angular contact ball slewing bearing, the structure of the existing ball loading plug was improved. There is a gap between the inner end face of the existing threaded ball loading plug and the bearing raceway, so the steel ball collides when rolling. After longterm use of the bearing, the ball loading plug is easy to be misplaced. The improved ball plug was the tapered pin insert lock structure. The ball loading plug and the bearing inner seat ring were integrated through the positioning taper pin and were processed , so that the consistency and consistency of the raceway were guaranteed. The locating taper pin limited the circular motion and axial motion of the ball plug at the same time. In order to optimize the movement of the positioning taper pin, the gasket and screw were designed; the O-ring was added to ensure the bearing sealing effect at the ball loading plug. The new structure of the ball loading plug can improve the stability performance of the slewing bearing effectively.