α- Amylase, also known as starch-1,4-dextrinase, is officially named α- 1,4-d-glucan glucoside hydrolase, which acts on starch and can be cut from the inside of starch, glycogen, oligomer or polysaccharide molecules in a random manner α- Maltose, oligosaccharide and glucose are produced by 1,4-glucoside bond. It is one of the most widely used enzyme preparations in industrial production.