The invention discloses a medicine for treating the radiation-induced pulmonary injury and a preparation method thereof, and belongs to the field of traditional Chinese medicines. The medicine comprises the following raw materials constituting effective ingredients: hypoestes purpurea, arrowroot, siegesbeckia orientalis, crepis phoenix, dendrobium jenkinsii wall, ardisia japonica, Chinese alpine rush, wedelia chinensis, tangerine leaf, silverleaf cinquefoil root, pecan, gecko, wood betony, thesium chinense, trichosanthes kirilowii maxim and Chinese squill. The medicine is suitable in compatibility of selected medicines, conforms to the theory of traditional Chinese medicine and pharmacy and modern medicine and pharmacology, has the effects of nourishing yin, engendering fluid, moisturizing lung and relieving cough, activating blood and dissolving stasis and relieving swelling and pain, has an obvious treating effect on treatment of the radiation-induced pulmonary injury, and short in treatment course, allows fast effect, does not relapse after healing, has no toxic and side effects, is low in cost, can achieve the purpose of treating both symptoms and root causes in cost, and has special effect and practicability, thus being worthy of wide popularization and application in clinic.