The invention relates to medical biological dressing and concretely relates to medical biological tooth desensitizer dressing and a preparation method thereof. The medical biological dressing is prepared from wormwood extract, water-soluble chitosan, sorbitol, silica, radix scutellariae extract, selaginella tamariscina extract, licorice root extract, uronic acid, calcium hydrogen phosphate, water-soluble mint oil, vitamin C and vitamin E. Through compatibility of the above raw materials, a tooth regeneration organ is maximally retained and activated, an oral environment is improved, vitamins are supplied, cell renewing is promoted, oral pH balance is kept, oral tooth restoration is promoted, pain and discomfort caused by cold, hot, acid and sweet stimulation to enamel, dentin, gingiva and exposed tooth root are eliminated, and dental nerve sensitivity to cold, hot, acid and sweet is reduced. The medical biological tooth desensitizer dressing has good effects of treating and preventing dentine sensitivity, can treat oral diseases such as swelling and aching of gum, gum bleeding and periodontitis and has effects of diminishing inflammation, relieving pain and stopping bleeding.