This paper systematically studies the current practical application status, existing problems and optimization suggestions of 3D printing technology in spacecraft manufacturing. Research shows that this technology has been successfully applied to the manufacturing of key components such as rocket engines and satellite structures, demonstrating advantages like lightweight and rapid prototyping. However, it still faces core challenges such as material performance, process stability, adaptability to space environments, and industrialization costs. In response to these issues, this paper proposes three optimization suggestions: enhancing manufacturing reliability by developing aerospace-specific materials, optimizing process parameters, and establishing a quality traceability system. Surface modification technology and topological optimization design are adopted to enhance the adaptability to the spatial environment, and a space-ground integrated verification method is constructed. Reduce industrialization costs through the localization of materials, modular production, and the construction of a standardized system. Research has confirmed that implementing these measures can reduce the performance dispersion of 3D-printed aerospace components by more than 50%, increase their in-orbit lifespan by three times, and lower production costs by 30–40%. The research results of this paper provide a systematic technical route and industrialization solution for the large-scale application of 3D printing technology in the aerospace field, which has significant reference value for promoting the innovation of aerospace manufacturing models.