Abstract: With the increase of aperture and observation frequency of dual-reflector antenna, the requirement for subreflector position precision is becoming higher and higher. When antenna is influenced by its own weight, wind, and temperature, etc., in order to better meet the requirements of high pointing accuracy and high electrical performance, based on the strain sensor and principle of modal superposition, the position, attitude, and morphology of subreflector is rapidly reconstruct using the strain values of deformed supporting legs and deformed subreflector surface, which is convenient for the real-time correction of the subreflector by adjustment mechanism, and to achieve a more accurate position matching of the main and subreflector surfaces, so the beam pointing errors and gain losses due to deformation of the antenna structure are reduced.