The invention discloses a traditional Chinese medicinal composition for improving irregular menstruation and a preparation method thereof. The traditional Chinese medicinal composition comprises the following components by the weight percentage: 1.2%-25% of salvia miltiorrhiza, 1.1%-20% of poria cocos, 1.2%-22% of angelica sinensis, 1%-30% of peach kernel, 1%-25% of folium sennae, 1%-25% of coix seeds, 1%-15% of galagal rhizome, 10%-30% of black-bone chicken, 5%-25% of donkey-hide gelatin, 1.1%-8% of vitamin C, 1.1%-8% of vitamin E, and 0.2-25% of auxiliary materials. With adopting of the traditional Chinese medicinal materials of pearls, black-bone chicken, donkey-hide gelatin, salvia miltiorrhiza, poria cocos, angelica sinensis, peach kernel, galagal rhizome, eucommia ulmoides, coix seeds and the like as main raw materials, and with compatibility and resultant action of various medicines, the human body internal functions can be conditioned and improved, obsessions of body weakness lassitude, deficiency cold syndrome and other symptoms are effectively improved, and especially, female irregular menstruation, dysmenorrhea and other symptoms are improved obviously.