The invention discloses an externally applied drug for treating bedsores, burns and scalds. The externally applied drug for treating bedsores, burns and scalds comprises: by weight, 40 to 80 parts of Chinese angelica, 20 to 40 parts of radix cynanchi atrati, 40 to 80 parts of pangolin scales, 5 to 15 parts of centipede, 20 to 40 parts of dragon's blood, 5 to 15 parts of borneol, 20 to 40 parts ofwhite wax and 300 to 800 parts of sesame oil. A preparation method of the externally applied drug for treating bedsores, burns and scalds comprises the following steps of adding 40 to 80 parts by weight of Chinese angelica and 20 to 40 parts by weight of radix cynanchi atrati into 300 to 800 parts by weight of sesame oil, heating until the raw materials are burned into carbon, filtering to removedrug dregs, adding pangolin scales and dragon's blood into the filtrate, stirring until sesame oil does not smoke, cooling to a temperature of 50 to 60 DEG C, adding borneol, white wax and centipede into the cooled filtrate with pangolin scales and dragon's blood, well stirring, and preparing a finished plaster. The externally applied drug for treating bedsores, burns and scalds has the functionsof cooling blood and clearing toxins, reducing swelling and dissipating binds, and removing slough and promoting growth of tissue. The clinical effect observation proves that the externally applied drug for treating bedsores, burns and scalds has obvious bedsore, burn and scald treatment effects.