Additive manufacturing, known as 3D printing, is gaining more attention in component weight reduction, model verification, complex structure integration forming, and damage repairing process. 3D printing technique is based on liquid and powder materials stack layer by layer, transforming CAD data to three-dimensional solids without molding or machining. In this work, a comprehensive introduction of 3D printing application in aerospace microwave devices has been accomplished. The basic concept and comparison of 3D printing is summarized. With the understanding of the research progress in 3D printing microwave devices, the development of space 3D printing technology is prospected.