The invention discloses a traditional Chinese medicine preparation for treating ulcerative colitis. The traditional Chinese medicine preparation comprises the following raw materials: bletilla striata, pericarpium granati, membranous milkvetch root, white paeony root, common yam rhizome, costustoot, skyblue broomrape herb, largehead atractylodes rhizome, Indian buead, divaricate saposhnikovia root, common macrocarpium fruit, Chinese magnoliavine fruit, golden thread and tangerine peel. Chinese pulsatilla root, dahurian patrinia herb and amur corktree bark are added for people with heavy dampness and heat and incessant dysentery. Officinal magnolia bark, bitter orange, kudzuvine root, charred malt, charred hawthorn fruit and charred medicated leaven are added for people with intestine and stomach dyspepsia, stomachache, abdominal distension and less ache after diarrhea. Chicken's gizzard-membrane, nutmeg and malaytea scurfpea fruit are added for people with incoordination between the liver and the spleen and heavy cold dampness in phlegm. Through the application of the traditional Chinese medicine preparation for treating ulcerative colitis, the purposes of checking diarrhea and reducing inflammation, resolving tetany and relieving pain, modifying local blood circulation and metabolism, enhancing the intestinal immune function and promoting the healing of ulcer can be reached. And through the application of the traditional Chinese medicine preparation for treating ulcerative colitis, the medicine can directly act on nidus; and meanwhile, the traditional Chinese medicine preparation for treating ulcerative colitis can be used for local washing and cleaning, and is simple and convenient in production process, less in toxic and side effects, convenient to apply, easy to produce, low in cost, short in healing time and relapse-free after healing.