The invention discloses a drug used for curing postnatal depression and a preparation method thereof. Varied ingredients of the drug are weighted in portions as following: 10 portions to 20 portions of radix bupleuri, 10 portions to 20 portions of roots of Chinese angelica, 10 portions to 20 portions of root of herbaceous peopny, 10 portions to 20 portions of root bark of tree paeony, 10 portionsto 20 portions of cape jasmine, 10 portions to 20 portions of mentha, 10 portions to 20 portions of poria cocos, 10 portions to 20 portions of rhizome of large-headed atractylodes, 10 portions to 20 portions of root of membranous mile vetch, 10 portions to 20 portions of light wheat, 10 portions to 20 portions of Chinese red date, 10 portions to 20 portions of radix curcumae, 10 portions to 20 portions of nard, 10 portions to 20 portions of lily, 10 portions to 20 portions of dried rhizome of rehmannia, 10 portions to 20 portions of Albizzia julibrissin durazz and 10 portions to 20 portions of licorice root. The drug used for curing the postnatal depression has simple preparation technology, low cost and obvious curative effect and can sooth the liver, reinforce spleen and stomach, clear heat and relieve restlessness, obey hepatic qi, clear healthy and lively vigor and can nourish the blood. The preparation method of the drug of the invention has simple technology, cheap raw materials, good curative effect without any toxicity or side effect, short curing time and good social and economic benefits.