Polylactic acid, also known as polylactide, belongs to the polyester family. Polylactic acid is a polymer obtained by polymerization of lactic acid as the main raw material. The raw material source is sufficient and can be regenerated. The production process of polylactic acid is pollution-free, and the product can be biodegradable and realize the circulation in nature, so it is an ideal green polymer material. Polylactic acid (PLA) is a new type of biodegradable material, which uses the starch raw material extracted from renewable plant resources (such as corn) to make lactic acid through fermentation process, and then converts into polylactic acid through polymer synthesis.