The invention relates to the technical field of medicines, and provides an externally applied medicine for treating wound ulcer, namely a fuchsia ointment, which is prepared from the following raw materials in part by weight: 10 to 15 parts of arctium root, 3 to 5 parts of centipede, 1 to 4 parts of scorpion, 5 to 8 parts of beehive, 5 to 8 parts of honeylocust, 5 to 10 parts of Sinkiang arnebia root, 5 to 10 parts of liquoric root, 5 to 10 parts of angelica dahurica, 5 to 8 parts of trogopterus dung, 5 to 10 parts of safflower, 1 to 5 parts of root of red-rooted salvia, 1 to 5 parts of Chinese angelica, 500 to 1,000 parts of sesame oil, 50 to 100 parts of yellow wax, 50 to 100 parts of white wax and 7 to 10 parts of storax oil. A preparation method for the externally applied medicine comprises the following steps of: immersing the arctium root, the centipede, the scorpion, the beehive, the honeylocust, the Sinkiang arnebia root, the liquoric root, the angelica dahurica, the trogopterus dung, the safflower, the root of red-rooted salvia and the Chinese angelica in the sesame oil for 2 days; decocting by using fire until the medicines are dried up; filtering decoction dregs; adding the yellow wax and the white wax; melting; cooling away from fire; adding the storax oil; stirring uniformly; putting into a porcelain container and sealing; burying under the ground for 7 days; and removing fire toxin by cupping to obtain the externally applied medicine. The fuchsia ointment has a reasonable formula, is complementary in medicinal synergy, can promote blood circulation and remove blood stasis, relieve swelling and pain and eliminate pus and promote tissue regeneration quickly, has simple and convenient processing technology, a simple using method, short treatment time and low cost, is praised by patients warmly, has certain social and economic benefits, and is worth popularizing.