The invention provides a traditional Chinese medicine composition for treating radiation proctitis, which is quick to take effect, good in effect and free from toxic and side effects and a preparation method thereof. The traditional Chinese medicine composition for treating radiation proctitis comprises the following raw material medicines by weight: 10-15g of Astilbe chinensis, 6-9g of dutchmanspipe root, 6-8g of Angelica sinensis, 12-15g of Ligusticum wallichii, 6-8g of Adenophora stricta, 10-15g of white hyacinth Bean, 6-8g of Rhizoma Atractylodis Macrocephalae, 9-15g of brookside astilbe, 9-15g of Bergenia crassifolia, 12-15g of medlar, 10-12g of Eclipta prostrate, 4-6g of liquorice, 10-15g of radix paeoniae alba, 15-30g of hairyvein agrimony, 15-20g of Cucurbitaceae, 15-18g of red umbilicaria, 9-12g of polygonum cillinerve ohwi, 5-10g of colla corii asini, 6-8g of pseudo-ginseng, 8-10g of radix scrophulariae, 10-15g of Scutellaria baicalensis and 9-12g of corydalis tuber. The preparation method of the traditional Chinese medicine composition comprises the following steps of: weighing the raw material medicines except pseudo-ginseng and colla corii asini; placing the raw material medicines in a marmite; adding 800ml of water to soak the raw material medicines; soaking for 60 minutes; decocting for 30 minutes by soft fire; filtering and obtaining a medicine liquid; then, adding 600ml of water, decocting for 20 minutes by soft fire, and obtaining a medicine liquid; grinding pseudo-ginseng and colla corii asini to fine powder, and then mixing the medicine liquids to obtain the composition.