The invention discloses a traditional Chinese medicine for treating chronic lung abscess. The traditional Chinese medicine is prepared from the following herbs in parts by weight: rhizoma phragmitis, Chinese watermelon kernel, semen coicis, peach kernel, Lobelia dauidii Franch, honeysuckle, fructus forsythiae, dandelion, heartleaf houttuynia herb, wild buckwheat rhizome, fresh Weijing, platycodon roots, baical skullcap roots, semen trichosanthis, bulbus fritillariae cirrhosae, radix codonopsitis, membranous milkvetch roots, trichosanthes roots, red paeony roots, radix angelicae sinensis, frankincense, myrrh, stir-baked squama manitis, Chinese honeylocust spine, divaricate saposhnikovia roots, angelica dahurica, poria cocos, roasted ephedra, almond, caulis sargentodoxae, gypsum fibrosum, ammannia auriculata, rhizoma fagopyri cymosi, Cryptolepis sinensis, ardisia crispa, Saxifraga punetata, cortex moutan, roots of rehmannia, figwort roots, bunge hackberry bark or stem, manchurian lilac bark, Pilea peltata Hance, pipevine, dwarf lilyturf turber, folium mori, citrus red, dried orange peel, fructus amomi rotundus, curcuma aromatica, Chinese thorowax, radix cyathulae, semen lepidii, rhizoma polygonati, teasel roots, humulus japonicus, dahurian rose fruit and liquorice. Clinical trials prove that the traditional Chinese medicine can safely and effectively treat chronic lung abscess.