The invention provides ointment for promoting the union of bone fractures and a preparation method thereof. The ointment consists of frankincense, myrrh, dragon's blood, catechu, pyrite, halloysite, dragon bone, yanhusuo, notoginseng root, sea horse, ground beetle, earthworm, leech, crab, snake slough, cicada molting, realgar, alum, dipsacus root, fortune's drynaria rhizome, rhubarb, Sinkiang arnebia root, camphor, borneol, musk, angelica dahurica, common clubmoss herb, garden balsam stem, clematis root, gentiana macrophylla and epimedium. The Chinese medicines are prepared into an ointment agent for external application or a pressure-sensitive adhesive ointment agent for external application. The ointment can relieve swelling and pain, promote blood circulation, remove blood stasis, clear and activate channels and collaterals, relieve heat, eliminate cold, dispel wind, eliminate dampness, promote the restoration consciousness with fragrance, enhance blood supply, activate the regeneration capacity of organism tissue and promote the union of the bone fractures, and has the good treatment effect on various bone fractures or the treatment of the bone fractures of postoperation.