Abstract: To ensure the directing performance of the multibeam antenna in a wide range of temperature variation, a method of designing the high thermal matching feed array is proposed in this paper. Firstly, the radial strip interface is used to realize the adaptive fitting of the feed phase center. Then the micro damage under the mechanical environment and the direction variation caused by the free clearance fit are solved by adopting the preset force spring. Lastly, the genetic algorithm is used to optimize the distributions of the interface position. The feed plate of a certain antenna is optimized by the above method, with simulation and test validation. It is shown that the maximum pointing error due to the thermal deformation is as low as 0.0203°, thus the requirement of the beam pointing deviation of not more than 0.025° can be met.