3D printing is a kind of rapid prototyping technology, which is a digital model file based on the use of special wax, powdered metal or plastic and other adhesive materials, through the way of layer by layer printing to construct the object technology. Often used in mold fabrication, industrial design and other fields to make models or for the direct manufacture of some products, the technology has applications in jewelry, footwear, industrial design, architecture, engineering and construction, automotive, aerospace, dental and medical industries, education, civil engineering, firearms and other fields.