The invention relates to a preparation method of the effective part of Hippophae rhamnoides. The method includes: crushing and screening aired Hippophae fruits or post-pressing Hippophae fruit residue, heating ethanol for reflux extraction, collecting extract, performing reduced-pressure recovery on the ethanol, condensing, enriching the condensate with macroporous resin, and vacuum-drying to obtain the total effective part of Hippophae rhamnoides. Hippophae rhamnoides contains 75-85% of the total effective part. The total effective part contains 35-50% of triterpene and 32-45% of total phenols. The results of in-vitro anti-oxidization and anti-bacteria experiments and bioactivity experiments show that the effective part of Hippophae rhamnoides is high in capacity of clearing free radicals in 2, 2-azino-bis(3-ethyl- benzothiazole-6-sulfonate) diammonium salt, high in inhibition on Staphylococcus aureus, and high in oxidation resistance and gram-positive bacterium inhibition. The product obtained by the preparation method is applicable to health foods, drugs, cosmetics or solid drink materials having the functions of protecting liver, lowering blood lipid, age defying, protecting gastric mucosa, antisepsis and anti-inflammation.