The invention discloses a medicinal composition for treating dog acute upper gastrointestinal hemorrhage and a preparation method thereof. The medicinal composition comprises the following raw medicinal materials: water shield, umbilicaria esculenta, tuber of dwarf lilyturf, leaf of omoto nipponlily, gardenia, false lily of the valley, iris, jasminum giraldii diels, prinsepia utilis, helwingia root, disporopsis fuscopicta, spanishneedles herb, kalanchoe, pseudo-ginseng, ginseng, root of red-rooted salvia, radix codonopsis, fiveleaf gynostemma herb, astragalus, white atractylodes rhizome, dried ginger, honeysuckle, fructus forsythiae, frankincense, myrrh and liquoric root. The medicinal composition has the beneficial effects that the main effects are to clear stomach, decrease internal heat and stop bleeding by astringency, the auxiliary effects are to nourish blood and tonify yin, the effects of strengthening the body resistance and eliminating evil can be realized, the immunity of the organism of a diseased dog is improved, and the medicinal composition has the advantages and characteristics of low cost, no medicine residue, pure naturalness, no toxic or harmful effect, high safety, good convenience, complete functions and the like in the aspect of treatment of the acute upper gastrointestinal hemorrhage. The medicinal composition has the advantages of easy and convenient preparation process, small toxic or side effect, convenience in drug administration, good curative effect, good tolerance, easiness in acceptance, easiness in manufacturing of the medicament and low cost.