The invention discloses a medicine dispensing device for plastic infusion bags, and the medicine dispensing device comprises a plastic infusion bag device, a syringe device, a syringe guiding rail moving device, a syringe recovery device, an ampoule device, a medicine bottle device, a classified recovery device, a plastic infusion bag conveying device and a PLC (Programmable Logic Controller). During operation, the whole device is controlled by the PLC to operate automatically; syringes, ampoules, medicine bottles and the plastic infusion bags are mounted manually; medicines are dispensed to the ampoules, the medicine bottles and the plastic infusion bags through the syringes; and after medicine dispensing is finished, the syringes, the ampoules and the medicine bottles fall into the syringe recovery device and the classified recovery device, and the plastic infusion bags are conveyed to an assigned department through the plastic infusion bag conveying device. The medicine dispensing device provided by the invention realizes intelligent integrated medicine dispensing of the plastic infusion bags, and the medicines can be dispensed to the ampoules, the medicine bottles and the plastic infusion bags simultaneously, so that the medicine dispensing speed and the efficiency are high, the medicine dispensing is safe and accurate, the working intensity of nurses is reduced, harm to personnel caused by errors in manual medicine dispensing operation is avoided, and zero contamination of the medicines is ensured.