The invention discloses an externally-applied Chinese medicinal preparation for losing weight, which comprises rhubarb, saffron, lotus leaf, liquoric root, borneol, Chinese waxgourd peel, cassia seed, aloe, costustoot, divaricate saposhnikovia root, honey, vinegar and the like. A preparation method comprises the following steps of: crushing the solid medicaments into fine powder, adding the fine powder, the honey and the vinegar into water, and fermenting at room temperature for two weeks to obtain the externally-applied Chinese medicinal preparation. The externally-applied Chinese medicinal preparation is prepared from pure Chinese medicinal herbs, is synergic, reasonable in compatibility, high in stability, safe, reliable, short in treatment course, low in cost, obvious in curative effect, practical and convenient, is administrated in vitro, does not have toxic or side effect and prevents the stimulation of oral preparations on stomachs and intestines to reduce the pain of patients, and clinical symptoms can disappear quickly.