The invention discloses an anti-cancer pain analgesic plaster and a preparation method thereof. The anti-cancer pain analgesic plaster is prepared from, by weight, 20-40 parts of dry tubers of corydalis yanhusuoW.T, 10-20 parts of frankincense, 10-25 parts of myrrh, 20-40 parts of piperaceae nom. Conserv., 20-40 parts of tubers of dioscorea bulbifera L., 10-20 parts of realgar, 20-40 parts of unprocessed radix aconiti, 20-40 parts of toddalia asiatica, 20-40 parts of herba paederiae, 20-40 parts of StephaniacepharanthaHayata., 20-40 parts of whole plants of datura stramonium L., 20-40 parts of dry tubers of aconitum kusnezoffii Reichb., 10-20 parts of dry tubers of sparganium stoloniferum Buch.-Ham., 10-20 parts of rhizoma curcumae, 40-60 parts of milkvetch roots, 10-25 parts of radix paeoniae alba, 20-40 parts of herb of pilea symmeria Wedd. var. salwinensis Hand.-Mazz., 5-15 parts of roots or whole plants of rhododendron molle G.Don, 5-15 parts of dry roots of phytolacca acinosa Roxb. or Phytolacca americana L. and 5-15 parts of borneol. According to the anti-cancer pain analgesic plaster, medicinal materials which have the effects of removing toxicity, eliminating stagnation, achieving anesthesia, easing pain, resisting bacteria, fighting against a cancer, improving a human immune function and the like are selected, reasonable matching is conducted, the medicinal materials act on organisms through acupoint application, the analgesic effect is achieved, and the plaster has the advantages of being obvious in effect of relieving cancer pain, rapid in pain relieving, safe, free of toxic and side effects, low in cost, free of addiction, simple in preparation technology and the like; by means of clinical tests, the effective rate reaches 98% or above, and the significant efficiency reaches 85% or above.