3D printing technology has developed rapidly in recent years. Because of its simple operation method and fast manufacturing speed, it is gradually applied to all walks of life. As an excellent biocompatible and degradable material, polylactic acid has become one of the most commonly used raw materials in 3D printing technology because of its good molding temperature and molding process. With the improvement of people's living standards, the requirements for 3D printing materials are becoming higher and higher, which makes the new composite materials based on polylactic acid develop rapidly in recent years. Polylactic acid and other materials are compounded to form new composite materials, which can make up for the shortcomings of polylactic acid itself, such as low hardness and poor conductivity. Through melt deposition molding technology, it can meet people's different needs in different fields, expand the application field of 3D printing, and make the composite materials with polylactic acid as the main body have great development prospects.