Pullulanase enzyme is produced from Bacillus licheniformis by deep fermentation. It can be widely used in beer, starch sugar, monosodium glutamate, alcohol, and other industries. Pullulan enzyme is a thermally stable debranching enzyme (cotyl-1, 6-glucosidase) applied at pH. It can hydrolyze the pentyl-1, 6-d-glycoside bonds in the liquefied starch to produce the straight chain polysaccharides containing thee-1, 4-d-glycoside bonds. It can act on amylopectin quickly and effectively, and cooperate with other enzymes (saccharifying enzyme, amylase of fungus) efficiently, so as to accelerate the reaction speed and increase the content of glucose and maltose. pullulanase assay is also tested on Shingenzyme.