When it comes to 3D printing, most people think that it is a new technology, but it is not the case. The idea of 3D printing originated in the United States at the end of the 19th century and was developed and promoted in the 1980s. It is called “the thought of the last century, the technology of the last century, and the market of this century”. For a long time, in the traditional manufacturing industry, problems such as difficult manufacturing of products with complex structures, high mold opening costs, and long production time have been very serious. Various problems and inconveniences have caused people to think about a rapid prototyping method. After continuous exploration and research, people finally achieved a new leap and invented 3D printing technology. In 1982, Charles served as the vice president of UVP, a manufacturer of ultraviolet equipment. Hull (CharlesW.Hull) tried to apply optical technology to the field of rapid prototyping. First, he put a liquid photosensitive resin that can be cured by ultraviolet light in a large container, and placed a lifting platform that can move up and down in the container, and an ultraviolet laser is installed above the container. Secondly, the lifting platform is initially parallel to the upper surface of the liquid, and the ultraviolet laser emitted by the ultraviolet laser irradiates the designated position on the surface of the liquid to solidify the liquid and complete a layer of printing. Then the lifting platform moves down the height of one layer (0.05~0.15mm), and the UV laser uses the same method to print the next layer. As the lifting platform continues to move down, the objects are printed layer by layer, and finally “accumulate” into a three-dimensional body. Finally, take the object out of the liquid and remove the support used for fixing on the lifting platform, then the real object that is the same as the CAD model in the computer can be obtained. Hull’s method broke through the technological limitations of rapid prototyping at that time, not only increased the speed of object printing, but also the printing volume could become very large. In 1986, Hull applied for a patent for the technology, and then he established 3DSystems, dedicated to commercializing the technology. In 1988, 3DSystems launched the world’s first commercial 3D printer based on stereolithography (Stereo Lithography Appearance, SLA) technology, marking the beginning of the commercialization of 3D printing. At the same time, in order to improve the accurate recognition and printing of CAD models by 3D printers, Hull developed the STL. file format. This file format triangulates the CAD model and uses many scattered and disorderly triangular facets to represent three-dimensional objects. Now it has become a common format for 3D printing.