After more than ten years of hard work, the Shi Yusheng research team of Huazhong University of Science and Technology has achieved a major breakthrough and developed the world's largest "3D printer." This "3D printer" can process parts with a maximum length and width of 1.2 meters. In theory, as long as the length and width of the part is less than 1.2 meters (no height limit), it can be "printed" by this machine. This technology transforms complex parts manufacturing into a simple bottom-up two-dimensional overlay, greatly reducing the complexity of design and manufacturing, making the production of exotic structures that cannot be processed in some traditional ways fast, and the production of some complex castings. The traditional three months were shortened to about 10 days. The largest laser 3D printer in the world with a maximum processing size of 1.8 meters participated in the research and development of Dalian University of Technology entered the commissioning stage. It adopts the unique technology route of “contour scanning” and can produce large-scale industrial samples and complex casting molds. This laser 3-D printing method based on "contour failure" has obtained two national invention patents. The laser 3D printer only needs to print the outline of each layer of the part, so that the sand coating resin of the sand line will be carbonized, and then the printed sand is heated and solidified in a 180° C. heating furnace and stripped after the processing. You can get a prototype or mold. The processing time of this printing method is proportional to the surface area of the parts, greatly improving the printing efficiency, and the printing speed can reach 5-15 times that of general 3D printing.