The invention discloses a traditional Chinese medicine preparation for treating eczema and a preparation method, and belongs to the field of traditional Chinese medicine. The effective component of the traditional Chinese medicine preparation is prepared from the following raw materials: cortex dictamni, herba polygoni avicularis, leaf of tree-of-heaven ailanthus, leaf of ringworm senna, fructus kochiae, flower of japanese kerria, radix sanguisorbae, auricled hedyotis herb, millet-tia ichthyoctona drake, herba salviae plebeiae, peltateleaf meadowrue herb, herba braseniae schreberi, rhizoma dioscoreae hypoglaucae, radix stemonae, folium eucalypti and gynura pseudochina. According to the traditional Chinese medicine preparation disclosed by the invention, selected medicinal materials are in suitable compatibility and confirm to a theory of traditional Chinese medicine and modern medicine, the traditional Chinese medicine preparation has the effects of clearing heat, detoxifying, relieving itching and pain, resisting bacteria, diminishing inflammation, clearing heat and expelling damp, strengthening the body resistance and tonifying deficiency, and the traditional Chinese medicine preparation has convenience in use, a good absorption effect and no adverse, toxic and side effects; through clinical verification, the traditional Chinese medicine preparation has a very good effect in relieving and treating the eczema, and is suitable for popularization and application of clinic treatment and nursing of the eczema.