The invention relates to oral medicine for treating breast gland lobular hyperplasia and a preparing method thereof. The medicine comprises angelica sinensis roots, radix paeoniae rubra, ligusticum wallichii, honewort, curcuma sichuaensis, tribulusterrestris, rinsed kelp, clean seaweed, processed rhizoma cyperi, pericarpium citri reticulatae viride, pseudobulbus cremastrae seu pleiones, dandelion and cornu cervi degelatinatum which respectively account for 1-3 parts of the mass of the medicine. The preparing method of the medicine includes the following steps that first-grade angelica sinensis roots, radix paeoniae rubra, ligusticum wallichii, honewort, curcuma sichuaensis, tribulusterrestris, rinsed kelp, clean seaweed, processed rhizoma cyperi, wine-treated pericarpium citri reticulatae viride, pseudobulbus cremastrae seu pleiones, dandelion and cornu cervi degelatinatum are selectively purchased according to the mass ratio, the cornu cervi degelatinatum is specially packaged and decocted first, the other drugs are put into a cloth bag after impurities and dust in the drugs are removed, a mouth of the cloth bag is tied, and then the drugs are prepared for use; the drugs are put into cold boiled water to be soaked for half an hour, then the soaked drugs and clear liquor of the soaked drugs are put into a drug-decocting machine together, cold boiled water is added until the water level is higher than the drugs by 35 mm, the drugs are decocted for 30 min for the first time, after liquid medicine is filtered out, tepid boiled water is added until the water level is higher than the drugs by 30 mm, the drugs are decocted for 30 min for the second time, and the liquid medicine is mixed and concentrated into of 1710 ml of traditional Chinese medicine liquid with the concentration of 50%.