Lactic acid is an important organic acid, and its yield and consumption are second only to the second organic acid of citric acid. It is reported that the consumption of lactic acid accounts for about 15% of the total consumption of organic acids. In recent years, due to the expansion of L-lactic acid in biodegradable plastics, the demand will increase at a relatively large rate. It is predicted that it may catch up or exceed citric acid after several years. Lactic acid is widely found in nature, and lactic acid is found in living organisms. Lactic acid, lactate and its derivatives are widely used in food, medicine, feed, chemical and other fields.