Abstract: To meet the demands of large-aperture，high surface accuracy of deployable antennas for high-resolution microwave remote sensing spacecraft in the future，a novel method called segmented method was proposed，which can effectively reduce the surface error caused by thermal deformation of the solid partial feed antenna in orbit.A parabolic solid partial feed antenna with a 5m aperture was employed，and then the effect of thermal deformation on the electrical performance of the antenna，especially the main beam efficiency，was analyzed with the finite element method.The influence of the support method with six points on the thermal deformation of the continuous solid surface antenna was investigated.Under the uniform temperature field with a difference of 200℃，the surface errors of cells with different shapes were analyzed，and then a hexagon shape was adopted as a segmented cell and the relationship between the surface error and the size was studied.The surface error and electrical performance of the antenna after being segmented by single cells with different sizes and arrangements were investigated，the effect of the splits among the segmented cells on the electrical performance of the antenna was verified，and the final segmented configuration was determined.The results show that the surface error decreases from 500μm to 5μm and the main beam efficiency decreases from 6.72% to 1.77% through the final segmented configuration.

Key words: space deployable antenna, high surface accuracy, thermal deformation, segmented method, main beam efficiency