Preparation method of dextrin with thermal viscosity stability

The invention relates to the technical field of dextrin processing, in particular to a preparation method of dextrin with thermal viscosity stability. The preparation method comprises the following steps that first, starch acidizing treatment is conducted, specifically, starch is acidized through a hydrochloric acid solution with the concentration being 6%-8%, thus the PH value of the starch is kept within the range of 2.0-2.2, and still standing for adsorption is conducted for two hours; second, pre-drying is conducted, specifically, the acidized starch is subjected to air flow drying to enable the moisture content of the starch to be decreased to 6% or below; and third, dextrin transformation is conducted, specifically, conduction oil is added into a jacket in a jacket reaction tank fora dextrinization reaction, the oil temperature of the jacket reaction tank is increased to 170 DEG C before the reaction, then the acidized starch treated in the second step is put into the jacket reaction tank, and trace hot