The production of PLA is rich in raw materials, such as sugar beet, corn and so on, and can be obtained through continuous cultivation of these materials. This will have a protective effect on limited oil and timber resources, as no oil or wood is used. Polylactic acid is the raw material of lactic acid, that is, hydroxy propionic acid, 2-hydroxy propionic acid. Because there is an asymmetric carbon atom in the lactic acid molecule, there are two enantiomers of D-type (right rotation light) and L-type (left light), and the DL-lactic acid, which is mixed with the same L-lactic acid and D-lactic acid, is not optical activity. Poly (L-lactic acid) was used as monomer.  The main industrial production of L-lactic acid is microbial fermentation and chemical synthesis of two major categories.