Abstract: In order to solve the problem of low computational efficiency of thermal deformation of large reflector antennas, this paper proposes a method to quickly predict the thermal deformation of antennas. Firstly, the thermal analysis model of the single panel of the antenna is established. Then, the deformation law of the antenna is analyzed by numerical calculation under different temperature differences between the upper and lower surfaces of the panel, the back frame and the panel, the back frame and the environment. Finally, a linear regression relationship is fitted to realize the rapid calculation of the thermal deformation of the structure. The regression relationship is used to predict the deformation of the antenna structure. The predicted results are in good agreement with the simulated deformation results. At the same time, the linear relationship between temperature difference and thermal deformation is verified by experiment. This method is applied to the thermal deformation calculation of 110 m reflector antenna. The results show that the structural deformation under sunshine is mainly the deformation of the back frame.