The invention discloses a medical infusion bag. The infusion bag is manufactured by using polypropylene and polyethylene and styrene-ethylene/butylene-styrene block copolymer. The infusion bag manufactured by adopting the technical scheme has the advantages that: the air-tightness and the steam resistance are excellent, the chemical stability is high, and the infusion bag is suitable to be used for manufacturing liquid medicinal products requiring high-temperature disinfection and sterilization; the transparence is high, and the detection of foreign materials when the infusion bag is produced and used is ensured; the softness is high, the falling resistance is high, the heat-sealing property is high, the high-temperature resistance is high, and the infusion bag can be sterilized at the temperature of 121 DEG C; because the infusion bag does not contain halogens, the infusion bag does not cause any environmental pollution when processed after use; and simultaneously, the barrier property is high, the chemical inertness and the biological inertness are high, the compatibility with medicaments is good, and the infusion bag can be used for packaging various kinds of common fluid, enteral nutrient fluid, parenteral nutrient fluid, dialyzate, flushing fluid, treating type large-capacity injection and the like.