Aiming at meeting the design accuracy requirements of the photoelectric tracking equipment,reducing and evaluating the influence of the deformation of the telescope main tube on the relative positions of the primary and secondary mirrors.The thermal stability analysis,static analysis and multi-physical field coupling analysis of the main tube are carried out by using ANSYS Workbench.The deflection angles of the primary mirror and the secondary mirror are analyzed,and the relevant modification suggestions for the structure of the main tube are put forward.According to the simulation results,the bending deformation of the main tube caused by the uneven solar radiation has the greatest influence on the deflection of the mirror.In order to reduce the influence of relative deflection between mirrors,the secondary mirror is mounted on the secondary mirror support frame,other than directly on the main tube,and the support connection between the secondary mirror and the focusing mechanism is strengthened.Again,the static analysis of the modified main mirror tube is carried out when it is horizontal,45 ° upward and 90 ° upward,and the multi-physical field analysis of the coupling of temperature field and gravity field is carried out.The results obtained from the simulation will provide some reference for the experimental calibration of the optoelectronic telescope.