The invention relates to a first-aid dressing used for traumatic wounds in a cold area and a preparation method of the dressing. The first-aid dressing comprises a medicinal film protective layer, a medicinal film layer, a heating layer, a back lining layer and a heating protective layer which are arranged in sequence; and the first-aid dressing can reach a heating temperature of 28 to 38 DEG C within 1-2 hours and can heat continuously for 4-6 hours. The first-aid dressing is prepared by the following steps: 1, preparing traditional Chinese extract and a matrix, and mixing to obtain a medicinal film plaster; 2, preparing heating material, bagging to obtain the heating layer; 3, preparing the heating protective layer and the back lining layer; and 4, preparing the first-aid dressing, packaging and disinfecting. The first-aid dressing can be used for pre-hospital first aid of a wounded person, can cover and protect the wound from further being infected, can enable the medicinal layer to reach a higher temperature through the internal heating material even in a cold area with a lower temperature, has a long time of curative effect, greatly reduces the dressing change frequency and shortens treatment cycle, facilitates disinfection and sterilization more, and alleviates the pains of the wounded person.