Abstract: This paper takes a 40 m antenna turntable bearing as the research object. According to the structural characteristics of the antenna, the stress analysis of turntable bearing in working state is introduced. Base on analyzing change of the turntable bearing reinforcement by mechanical simulationbefore and after,a method that strengthening the structural accuracy of turntable bearing is put forward.The results show that the accuracy of azimuth rotationcan be improved through by reinforcing the inflexibility of the turntable bearing of 40 m antenna. Compared with the characteristics of three row cylindrical roller bearing in application, it has the effect on changing the force state by optimizing the internal structure design of the turntable bearing. It is reference significance for the development of azimuth rotation of large antenna.