The present invention relates to the technical field of food processing. Disclosed is a dextrin fractionation method. The principle of the present invention is based on an incompatibility between a starch degradation product (dextrin) and polyethylene glycol in an aqueous solution, and the incompatibility between the dextrin and the polyethylene glycol is more remarkable when the molecular weight of the dextrin is greater, such that the concentration of the polyethylene glycol is gradually increased when the polyethylene glycol is gradually added in a dextrin aqueous solution, thereby stepwise precipitating dextrin components having molecular weights from large to small. The dextrin fractionation method comprises the steps of dextrin solution preparation and dextrin fractionation, and comprises: using tapioca starch as a raw material, degrading for 3 days at a temperature of 40°C via n-butyl alcohol and hydrochloric acid to obtain dextrin, dissolving the dextrin in distilled water to prepare 100 mL of a dextrin solution having a mass concentration of from 0.9% to 3.6%, adding 5 g of polyethylene glycol, heating and stirring until the solution is clear and cooling in air to a temperature of 25°C, storing for 24 hours at a temperature of 25°C, centrifuging, drying in an oven and grinding to obtain a fractional component 1 continuously adding 5 g of the polyethylene glycol to a supernatant and repeating the above process to obtain a fractional component 2 and repeating the above process until the added amount of the polyethylene glycol is 60 g to obtain 9-11 dextrin components.La présente invention se rapporte au domaine technique du traitement des aliments. Linvention concerne un procédé de fractionnement de dextrine. Le principe de la présente invention est fondé sur une incompatibilité entre un produit de dégradation damidon (dextrine) et le polyéthylène glycol dans une solution aqueuse, et lincompatibilité entre la dextrine et le polyéthylène glycol est plus remarq
