Abstract: With the rapid development of information technology in modern society, the space-air-ground integrated network has been proposed to solve the limitation problem caused by geographical location in traditional communication technology, which puts forward higher requirements for electronic information technology. Among them, 3D printing technology can realize the high-precision machining of RF devices, circuits and systems with multi-material and complex structures, saving the design and manufacturing time and realizing the integration of complex structures without installation and debugging, and greatly reducing the weight of the product. Aiming at the reliability problem of 3D printed antenna, this paper established a finite element analysis model based on multiple physical fields, taking into account multi-dimensional variables such as working environment, structure and material, and studied the influence of temperature and stress on the RF and mechanical structure performance of one kind of 3D printed antenna. The multi-physics simulation method and the simulation results are of guiding significance for understanding the failure mechanism of spaceborne 3D printing devices.