The invention discloses a traditional Chinese medicine for treating cancer. The traditional Chinese medicine is characterized by being composed of a medicine for external application and a medicine for oral administration, wherein the medicine for external application comprises the following raw materials in parts by weight: Common Nepenthes, crotalaria sessiliflora, glaucescent fissistigma root, radix clematidis, schisandra chinensis and lotus pollen; the medicine for oral administration is composed of mullet bone powder, Kangyan powder and another 10 Chinese medicine raw materials in parts by weight, wherein the 10 Chinese medicine raw materials are lindera aggregata flower, korean raspberry root, lindera angustifolia, phyllanthus urinaria, sea honeylocust, Chinese mosla herb, red cassia, chirita fimbrisepala, mahonia and tamariskoid spikemoss herb, or tamariskoid spikemoss herb, chirita fimbrisepala, purple bergenia herb, evergreen mucuna stem, caulis spatholobi, japanese ardisia herb, winter jasmine, gingko, eucommia ulmoides and ligusticum wallichii, or ligusticum wallichii, white atractylodes rhizome, angelica sinensis, radix rehmanniae, prepared rhizome of rehmannia, radix bupleuri, oriental wormwood, artemisia indica, hairyvein agrimony and the root of three-nerved spicebush. The traditional Chinese medicine for treating cancer and the preparation method thereof disclosed by the invention have the advantages that the method is simple and convenient, the prepared traditional Chinese medicine is capable of effectively treating cancer and preventing recurrence of cancer without harmful and side effects on human body health.