Novel method for preparing resveratrol by separating from rhizoma polygoni cuspidati component

The invention belongs to the field of extraction and separation of plant natural components, in particular to a novel method for preparing resveratrol by separating from a rhizoma polygoni cuspidati component. The method comprises the following steps: extracting rhizoma polygoni cuspidati continuously by ultrasonic water to obtain a rhizoma polygoni cuspidati extracting solution; directly and continuously adsorbing the extracting solution through a macroporous resin; eluting a resin with a solvent to obtain a polydatin mother liquor; concentrating the mother liquor and removing the solvent toobtain a crude polydatin product; separating the crude polydatin product with a silica gel column to obtain high-content polydatin; converting the high-content polydatin with a polydatin specific enzyme to obtain a resveratrol solid precipitate; and recrystallizing to obtain a pure resveratrol product. The process can also perform enzyme treatment on the crude polydatin product to prepare the resveratrol product with the