Method for preparing resveratrol extract by using waste residue from grape winery as raw material

The invention provides a method for preparing resveratrol extract by using waste residue from a grape winery as a raw material. The process flow of the method comprises the following steps: pre-treating the waste residue from the grape winery; extracting with a solvent; concentrating, and centrifuging; purifying with macroporous resin; concentrating; and carrying out spray drying so as to obtain the finished product. In the extract produced by using the method, the content of resveratrol is more than 10%; the extract is purplish red in color and bright in tincture; and compared with the conventional cuspidatum resveratrol extract at the market, the resveratrol extract in the invention contains a large amount of strong oxidation-resisting polyphenol substances and natural haematochrome harmless to a human body besides the resveratrol, and hardly contains archen. According to the invention, the process is simple, the operation is convenient, the cost is low, the waste residue from the grape winery is turned into wealth, and the officinal value of the waste residue is fully utilized, thereby being beneficial to comprehensive utilization of grape; and the waste residue from the grape winery can be used as a raw material of a medicament or food.