The invention discloses traditional Chinese medicine liquid for treating skin itch and a preparation method, belonging to the field of traditional Chinese medicines. The traditional Chinese medicine liquid disclosed by the invention comprises the following effective components: white loosestrife herb, bunge corydalis herb, jasminum polyanthum, garlic, swamp violet, Indian damnacanthus herb, emblic leafflower leaf, japanese white birch bark, alate senna leaf, Chinese juniper leaf, redfruit actinodaphne root and leaf, calabash, nakedflower beautyberry branchlet and leaf, rhizoma nardostachyos, wadalee-gum-tree and arnica montana. The selected medicinal materials in the traditional Chinese medicine liquid disclosed by the invention are properly compatible and accord with the theories of traditional Chinese medicines and modern medicines; furthermore, the traditional Chinese medicine liquid disclosed by the invention has the effects of clearing heat, disinfecting, eliminating blood-heat and stasis, dispelling the wind, dehumidifying, diminishing swelling and relieving itching, has obvious curative effects on skin itch caused by the systematic diseases, such as inflammatory dermatosis, uremia, primary cholestasis, polycythemia vera and the like, and has the advantages of being short in treatment course, rapid in effect, non-recurrent after healing, safe and free from toxic and side effect; the purpose of treating both symptoms and root causes can be achieved, and therefore, the traditional Chinese medicine liquid for treating skin itch disclosed by the invention is worthy of being widely popularized and applied.