Abstract: The large temperature gradient in the circumferential and axial directions of the bearing can lead to a seizure failure. The thermal design, the thermal simulation and the thermal vacuum experiment based on solar simulator are carried out, and the detailed temperature distribution of the SADA is obtained. The light barrier and the temperature uniformity measures are taken to reduce the temperature gradient and the influence of the external heat flux. In the thermal experiment, the external heat flux is the same as that in the winter solstice. The boundary temperature of the cabin plates is 25℃. Eighty-eight thermal couples are installed to collect the temperature data for the SADA. The bunch of cables, the slip ring assembly and the electrical brushes are the locations with higher temperature. The maximum temperature differences are 1.2℃ and 8℃ on the head face and the end face of the bearing in the circumferencial direction. The maximum temperature difference is 6.8℃ between the head face and the end face of the bearing in the axial direction. The SADA can work well under these temperature conditions. It is shown that the SADA design and the thermal control design are reasonable. The results of the thermal simulation are consistent with the experiment results. The results are also verified by the on-orbit data. The thermal analysis model, the experimental methods and the test results can be used in the subsequent thermal designs and the temperature distribution researches of the SADA under different working conditions.