The invention discloses a traditional Chinese medicine composition for treating onychomycosis, which comprises the following Chinese herbal medicine components in parts by weight: 15-30 parts of golden larch bark, 10-25 parts of radix sophorae flavescentis, 10-25 parts of salvia miltiorrhiza, 8-15 parts of vietnamese sophora root, 10-23 parts of fructus cnidii, 10-19 parts of sulfur, 5-17 parts of calomel, 3-15 parts of nux vomica, 6-16 parts of borax, 11-21 parts of calamine, 13-21 parts of nidus vespae, 1-6 parts of minium, 3-9 parts of alum, 2-8 parts of rangooncreeper fruit, 12-21 parts of chinaberry bark, 7-13 parts of agrimony bud, 2-11 parts of Chinese torreya seed, 3-10 parts of barbed skullcap herb, 12-18 parts of houttuynia cordata, 15-21 parts of fructus forsythiae, 11-25 parts of bezoar, 13-19 parts of dahurian patrinia herb, 7-15 parts of Chinese violet herb and 3-9 parts of gentian. The composition adopts a Chinese herbal medicine component formula, has high safety and small side effect, treats both principal and secondary aspects of diseases, and achieves the effect of thoroughly treating onychomycosis.