The invention discloses an external-use plaster for tonifying spleen and tonifying stomach and a preparation method thereof. The plaster comprises nude fern herb, fennel root, kiwi fruit vine, root of bergamot, mangLietia yunnanensis fruit, sago leaf, flos mume, common perilla fruit, rhizome of large leaf japanese ginseng, carum carvi f. gracile, dried tangerine or orange peel, immature bitter orange, volatile fine stuff, a penetrating agent, a matrix, an antioxidant, and far infrared ceramic powder. The preparation method comprises the following steps: extracting active ingredients of the traditional Chinese medicine materials according to the properties of the traditional Chinese medicine materials by virtue of methods of juicing, alcohol-extracting, decoction-extracting respectively, concentrating the active ingredients into thick paste, drying and pressing the paste into fine powder at a low temperature, sieving repeatedly to obtain medicine powder; adding the medicine powder and ingredients such as the volatile fine stuff, the penetrating agent and the antioxidant into the matrix, and preparing the mixture into paste. The external-use paste for tonifying spleen and tonifying stomach disclosed by the invention is reasonable in compatibility of materials, capable of regulating flow of qi and invigorating stomach, tonifying spleen, regulating the middle warmer and appetizing, aiding digestion, treating gastric disorder causing nausea and vomit and constipation, and the like, exact in curative effect and free of side effect.