The invention discloses an externally applied traditional Chinese medicine powder for diminishing inflammation and swelling, which is prepared from the following raw material medicines by weight percentage: 20-30% of realgar, 25-35% of rhubarb, 10-20% of turmeric, 10-20% of cortex phellodendri, and 10-20% of bulbus fritillariae thunbergii. The externally applied powder for diminishing swelling isprepared by the compatibility of only five raw material medicines, has the efficacies of promoting blood circulation and removing blood stasis, diminishing swelling and relieving pain, expelling stasis and stagnation, and promoting pus discharge and tissue regeneration. The externally applied traditional Chinese medicine powder is simple in compatibility, distinct in treatment effect, and short in course of treatment, and does not have toxic or side effect. The externally applied powder for diminishing swelling can treat acute and chronic lobular hyperplasia of mammary glands, lymphnoditis, mumps, traumatic injuries, lipoma, furuncle, pustule of finger tip, paronychia, tinea unguium, external piles, anus abscess and hemangioma, with wide treatment range and low cost, and also can be used for treating mammary gland disease and foot-and-mouth disease of cows, with very good treatment effect.