The invention discloses a method for extracting dihydromyricetin from vine tea, including the following steps: (1) vine tea dry leaves are weighed, subject to microwave radiation treatment by a microwave oven and then smashed; (2) the particles are added into a microwave reverse flow extractor, water is added, microwave extraction and filtering are carried out, thus obtaining filtration A and residue A; (3) the residue A is processed according to the method in the step (2), thus obtaining filtration B and residue B; (4) residue A and residue B are merged and added into the microwave reverse flow extractor, ethanol is added, microwave extraction is carried out for 30-60min and then filtering is carried out, thus obtaining filtration C; (5) the filtrations A, B and C are merged, and then concentration, crystallization and drying are carried out. The invention has simple technology and convenient operation, extraction ratio of dihydromyricetin can reach 47.3%, purity can reach 85%, the required organic solvent is less, operating safety is good, no high temperature furnace is required for heating, energy consumption is reduced, and production cost is saved.