Method for preparing trehalose from starch

The invention provides a method for preparing trehalose from starch, and belongs to the technical field of trehalose. The method comprises the steps of starch milk preparation, liquefaction, carrier preparation, enzymolysis, filtration, decoloration, ion exchange, crystallization and centrifugal drying. The step of preparing the carrier comprises the steps of preparing a mixed sulfuric acid solution, reacting, post-treating and modifying; the step of preparing the mixed sulfuric acid solution comprises the following steps: mixing cetyltrimethylammonium bromide, carboxymethyl cellulose and lauryl sodium sulfate, then carrying out ultrasonic treatment, controlling the ultrasonic time to be 10-14 minutes and the ultrasonic frequency to be 10-12 kHz, adding the mixture into a sulfuric acid solution after ultrasonic treatment is finished, and uniformly stirring to obtain the mixed sulfuric acid solution. The prepared trehalose is high in purity and good in yield, the reusability of the recovered and loaded modifie