The invention discloses a lumbago emplastrum and a preparation method thereof. The lumbago emplastrum is prepared from 200-300 parts of parasitic loranthus, 200-300 parts of eucommia ulmoides, 80-120parts of radix achyranthis bidentatae, 80-120 parts of ground beetles, 80-100 parts of rhizoma corydalis, 80-100 parts of aloes, 80-100 parts of paniculate swallowwort roots, 80-100 parts of girald daphne bark, 80-100 parts of Chinese alangium roots, 50-60 parts of pseudo-ginseng, 50-60 parts of olibanum, 50-60 parts of radix clematidis, 50-60 parts of myrrh, 30-50 parts of large-leaved gentian, 30-50 parts of radix angelicae pubescentis, 30-50 parts of notopterygium roots, 30-50 parts of Chinese angelica, 30-40 parts of ligusticum wallichii, 30-40 parts of white paeony roots, 30-40 parts of semen coicis and 20-40 parts of borneol. According to the lumbago emplastrum and the preparation method, the parasitic loranthus and the eucommia ulmoides serve as main materials and are matched with the radix achyranthis bidentatae, the ground beetles, the rhizoma corydalis, the aloes, the paniculate swallowwort roots, the girald daphne bark, the Chinese alangium roots, the pseudo-ginseng, the olibanum, the radix clematidis, the myrrh, the large-leaved gentian, the radix angelicae pubescentis, the notopterygium roots, the Chinese angelica, the ligusticum wallichii, the white paeony roots, thesemen coicis and the borneol, no medicines with the toxicity and the paralytic function are added, no toxic or side effects are caused, lumbago can be safely and effectively relieved, in addition, thepreparation process is simple and convenient, and the production and application values are very high.