Application areas of 3D printing: 1. Industrial manufacturing: product concept design, prototyping, product review, functional verification; making mold prototypes or directly printing molds, and directly printing products. 3D printed small unmanned aircraft, small cars and other concept products have come out. 3D printed household appliance models are also used in corporate publicity and marketing activities. 2. Cultural creativity and digital entertainment: artistic expression carriers with complex shapes and structures and special materials. The science fiction movie 'Avatar' uses 3D printing to shape some characters and props, and the 3D printed violin is close to the level of craftsmanship. 3. Aerospace, national defense and military industry: direct manufacturing of parts and mechanisms with complex shapes, fine dimensions, and special performance. 4. Biomedicine: artificial bones, teeth, hearing aids, artificial limbs, etc. 5. Consumer goods: design and manufacture of jewelry, apparel, footwear, toys, creative DIY works. 6. Building engineering: building model wind test and effect display, building engineering and construction (AEC) simulation. 7. Education: Models verify scientific hypotheses and are used in experiments and teaching in different subjects. In some middle schools, ordinary universities and military academies in North America, 3D printers have been used for teaching and scientific research. 8. Personalized customization: network-based data download, e-commerce personalized printing customization service. The development status and problems of the domestic 3D printing industry.