The invention provides medicine for treating skin swelling and pain and a preparation method thereof. The medicine comprises, by weight, 60g of scorpion, 50g of centipede, 20g of radix sophorae flavescentis, 30g of cortex phellodendri, 30g of fructus cnidii, 30g of cortex dictamni, 20g of radix lithospermi, 20g of borneol and 1000g of sesame oil. The preparation method includes: preparing the rawmaterials, to be more specific, weighing the raw material according to the weight, slightly moistening the weighed radix lithospermi with a small amount of clean water, and grinding the borneol for standby; soaking the raw materials, to be more specific, placing the sesame oil into a heating barrel, and soaking the radix sophorae flavescentis, the cortex phellodendri and the cortex dictamni into the sesame oil for 24 hours. The medicine for treating the skin swelling and pain and the preparation method thereof have the advantages that the raw materials of the medicine are easy to obtain, the preparation method is simple, and the medicine is low in cost, capable of treating red and swollen skin, skin hotness, skin pain, skin itching and the like caused by intractable eczema, neurodermatitis, mosquito bite, foot and hand tinea combined infection, foot and hand furuncle, herpes zoster, urticarial and the like, good in curative effect and short in treatment course.