The invention discloses a medicinal preparation for treating stasis dermatitis. The medicinal preparation is characterized by being prepared from the following medicinal materials by weight: 150-300 g of fresh herb of lawn pennywort, 75-150 g of fresh herba lysimachiae, 100-150 g of camellia oil, and 3-6 g of aluminite. A preparation method of the medicinal preparation comprises the following steps: pounding fresh herb of lawn pennywort, fresh herba lysimachiae and aluminite at the weight ratio of 50 to 25 to 1 to form medicinal velvet, and placing the medicinal velvet into the hot camellia oil for processing; in use, applying the obtained product to the affected part, thus the efficacies of dredging the blood capillaries of a patient, promoting the metabolism, and relieving itching are achieved, meanwhile, the efficacies directly reach the focus, so that the effects of dispelling stasis, removing damp toxins, and softening the skin tissue are achieved, and finally, the treatment purpose is achieved. The medicinal preparation provided by the embodiment of the invention also can be prepared by smashing dry herb of lawn pennywort, dry herba lysimachiae and aluminite at the weight ratio of 12 to 6 to 1, and then processing the smashed product in the hot camellia oil; and in use, applying the finished product to the affected part. The medicinal preparation is prepared from the pure natural medicinal materials, is free of hormone and chemical medicines, and has the advantages of low preparation cost, good treatment effects, and no toxic and side effects.