The invention discloses a traditional Chinese medicine composition for treating animal enteritis or diarrhea and a preparation method of the traditional Chinese medicine composition. The traditional Chinese medicine composition comprises the components in part by weight as follows: 25-50 parts of mongolian oak bark, 5-20 parts of figs, 5-20 parts of herba andrographitis, 2-12 parts of folium isatidis, 2-12 parts of desmodium triquetrum, 2-12 parts of red-knees herbs, 5-20 parts of herba portulacae and 5-15 parts of astragalus mongholicus. The traditional Chinese medicine composition has the effects of clearing heat, promoting diuresis, detoxifying, detumescence, astringing and checking diarrhea and has obvious curative effects for animal enteritis or diarrhea. Clinical curative effect observations prove that the traditional Chinese medicine composition is rapid, reliable and authentic in curative effect for animal enteritis or diarrhea; and is non-toxic and harmless for animals, safe and reliable. In a clinical usage process, no untoward effects of the animals are observed, and the clinical usage is safe.