The invention discloses a method for extracting biflavone from Chinese arborvitae twig and leaf. The method comprises the following steps: putting the Chinese arborvitae twig and leaf into a homogenizing machine, mixing and homogenizing with petroleum ether in the homogenizing machine, extracting for 10 to 15min, concentrating an extracting solution, adsorbing a concentrated solution by macroporous resin, and recrystallizing a crystal substance by a 70% ethanol solution and drying to obtain the biflavone. Compared with the prior art, the method disclosed by the invention has the following beneficial effects: 1, a plant homogenization extraction method is utilized to process the raw material, liposoluble constituents of chlorophyll and the like are removed, heating is avoided at the same time, and the biflavone ingredient is effectively prevented from being damaged; 2, compared with a traditional technology, microwave extraction has the advantages of high extraction efficiency, strong selectivity, ability in saving time, ability in saving solvents, ability in saving energy, small pollution and the like.