The invention discloses a pharmaceutical composition for preventing a plant virus disease. The pharmaceutical composition is prepared from the following components in percentage by weight: 1 percent to 10 percent of amantadine hydrochloride, 10 percent to 30 percent of moroxydine hydrochloride, 3 percent to 15 percent of salicylic acid, 3 percent to 8 percent of brassinolide, 35 percent to 45 percent of bamboo vinegar or wood vinegar, 3 percent to 5 percent of camphor oil, 8 percent to 16 percent of a pesticide emulsifier, 5 percent to 10 percent of ethyl alcohol and 5 percent to 8 percent of orange peel extract liquid. The orange peel extract liquid is distilled liquid which is obtained by mixing fresh orange peels with the bamboo vinegar in the ratio of 1 to 1 and performing distillation in water by a distillation method. The selected raw materials are low in cost and easily obtained; the pharmaceutical composition is simple in preparation process, convenient to use, and harmless to a human body and crops, can promote the normal development of plants, can multiply the yield, and is a first choice drug for preventing and treating the plant virus disease; the prevention and treatment effect on the plant virus disease can reach over 70 percent.