The invention discloses a traditional Chinese medicine composition for treating colon cancer and a preparation method thereof. The traditional Chinese medicine composition mainly comprises the following raw medicinal herbs: indigo naturalis, tuckahoe, coix seed, taraxacum officinale root, herba violae, Mangnolia officinalis, houttuynia cordata, patrinia, angelica sinensis, radix paeoniae alba, Chinese lobelia herb, radix sophorae falvescentis, dried orange peel, medicated leaven, rhizoma cyperi, aspongopus, prepared frankincense, prepared myrrh, corydalis tuber, manis pentadactyla, raw astragalus mongholicus, radix notoginseng, charred sanguisorba officinalis, rhizoma sparganii, curcuma zedoary and the like. The Traditional Chinese medicine composition can be prepared into any one common oral preparation according to a conventional traditional Chinese medicine composition method. The invention can remarkably improve symptoms of frequency increase of defecate, blood and mucus brought in the defecate, bellyache, diarrhea or astriction, intestinal obstruction and malaise, weight reduction, anemia and the like, and has accurate clinical treatment effect, remarkable treatment effect and rapid effect taking. Because of being combined by basically adopting medicinal and edible medicines specified in National Formulary, the traditional Chinese medicine composition has the advantages of low cost, basic no toxic and side effect, and the like.