The invention discloses a method for preparing total flavonoids of hovenia acerba. The method adopts one optional method of the solvent extraction method, the solvent extraction method, the macro-porous resin adsorption method, the liquid-liquid countercurrent distribution chromatography, the supercritical fluid extraction method or the column chromatography, or the free combination of the methods. The total flavonoids of hovenia acerba is prepared from any one part of hovenia acerba, such as fruit stems, fruits, seeds, seed-cases, roots, stems, leaves, flowers, branches, skins, skin and fruit residues, etc., and the combination thereof. The prepared total flavonoids is a combination of various flavonoid active components, wherein the total flavonoids comprises the main active components as follows: quercetin, kaempferol, (+)-dihydromyricetin, myricetin, north hovenia acerba alcohol, (+)-pyrocatechin, hovenia acerba I, hovenia acerba II, hovenia acerba III and the derivates thereof; the total percentage composition of various flavonoid components by the weight is 5% to 100%; and the preparation method is applicable to pharmaceutical industry, food industry, cosmetic industry and health-care product industry.