Abstract: In the fields of aerospace, biomedicine, architecture, and manufacturing, 3D printing technology demonstrates unique application potential. This paper reviews its typical applications in customized medical implants, lightweight aerospace components, architectural structures, and rapid prototyping in manufacturing, and discusses technical challenges such as material limitations, printing accuracy, and cost efficiency. Future development trends include diversification of material systems, improvement of printing speed and precision, continuous expansion into new application domains, and deep integration with cutting-edge technologies such as artificial intelligence and the Internet of Things. Meanwhile, the potential of 3D printing to promote environmental sustainability and efficient resource utilization will be further explored. With the advancement of standardization and normalization, 3D printing technology is expected to achieve broader application and industrialization, thereby bringing revolutionary changes to the manufacturing industry.