The invention relates to the field of pharmaceutical formulation, and particularly to a traditional Chinese medicine decoction for treating onychomycosis as well as tinea manus and pedis. The traditional Chinese medicine decoction is characterized by comprising raw medical materials in parts by weight of: 25-35 parts of cortex pseudolaricis, 20-30 parts of common cnidium fruit, 15-30 parts of sessile stemona root, 10-20 parts of lilac, 25-35 parts of cotex dictamni, 10-15 parts of garden balsam stem, 15-25 parts of paniculate swallowwort root, 15-20 parts of baical skullcap root, 20-35 parts of radix sophorae flavescentis, 15-25 parts of dried alum, 15-20 parts of alum, 20-30 parts of gallnut, 15-25 parts of belvedere fruit, 15-25 parts of Chinese rhubarb, 15-25 parts of Japanese knotweed, 20-25 parts of chaulmoogratree seeds, 15-25 parts of capsicum annuum, 20-25 parts of golden cypress and 15-25 parts of garlic, wherein the 19 raw medical materials above after being mixed are soaked in water; and slag is removed after the mixture is decocted to obtain filter liquor. The traditional Chinese medicine decoction is used for treating the onychomycosis as well as the tinea manus and pedis, has good curative effects, is convenient to use and can eradicate the onychomycosis as well as the tinea manus and pedis thoroughly without recrudescence and side effect.