The invention relates to a traditional Chinese medicine preparation for treating psoriasis. The preparation is a traditional Chinese medicine granule prepared from the following traditional Chinese medicine decoction pieces in parts by weight: 6-20 parts of rhizoma smilacis glabrae, 6-20 parts of radix rehmanniae recen, 6-20 parts of semen coicis, 6-20 parts of lalang grass rhizome, 3-12 parts of cortex dictamni, 1-12 parts of root of common peony, 1-12 parts of angelica sinensis, 1-12 parts of moutan bark, 1-12 parts of fructus kochiae, 1-12 parts of oldenlandia diffusa, 1-10 parts of radix sophorae flavescentis, 1-10 parts of fried gardenia, 1-10 parts of radix clematidis, 1-8 parts of zaocys dhumnade, 1-8 parts of honeycomb, 1-8 parts of radices sileris, 1-8 parts of liquorice and 1-8 parts of lithospermum. The preparation method comprises the following steps of: extracting: respectively taking each Chinese medicine decoction piece, decocting for two times with water, 1-2 hours each time; preparing clear cream: concentrating decocted solution to be required relative density, to obtain the clear cream of each Chinese medicine decoction piece; spraying pelletizing: carrying out spraying pelletizing or spraying drying to the clear creams, preparing to be fine powder, mixing uniformly with auxiliary materials, to obtain traditional Chinese medicine granules; and packaging respectively. The preparation is significant in effect, high in cure rate, low in recurrence rate and low on dosage.