The invention discloses a drug composition for tonifying kidney and yang and a preparation method thereof and belongs to the technical field of drugs. The drug composition comprises the following components in parts by weight: 5-10 parts of ginseng, 2.5-5 parts of milk vetch, 2.5-5 parts of fructus psoraleae (fried with salt), 2.5-5 parts of morinda officinalis (prepared), 2.5-5 parts of cistanche, 2.5-5 parts of dogwood (prepared), 2.5-5 parts of barbary wolfberry fruit, 2.5-5 parts of raspberry, 2.5-5 parts of prepared polygonum multiflorum, 2.5-5 parts of eucommia bark (prepared by salt), 2.5-5 parts of cinnamon, 2.5-5 parts of semen cuscutae, 2.5-5 parts of Chinese yam, 2.5-5 parts of fructus amomi, 2.5-5 parts of white atractylodes rhizome, 2.5-5 parts of radix ophiopogonis, 2.5-5 parts of asparagus cochinchinensis, 2.5-5 parts of schisandra chinensis, 2.5-5 parts of prepared rehmannia root, 2.5-5 parts of chrysanthemum, 2.5-5 parts of golden cypress (fried with salt), 2.5-5 parts of plantain seed (fried with salt), 2.5-5 parts of platycladi seed and 2.5-5 parts of polygala tenuifolia (prepared). The preparation made by extracting and processing the drug composition formed by the twenty four medicines has the definite effects of tonifying kidney and yang, replenishing qi and enriching blood, securing essence and stopping diarrhea, improving immunity of the organism, obviously improving sexual function of men and improving quality of sexual life, can be used for preventing and treating sexual dysfunctions such as impotence and premature ejaculation and has better clinical effect.