Abstract: The present invention provides a polyolefin co-extruded film for liquid-liquid multi-chamber infusion bags, and a preparation method and application thereof, relating to the technical field of infusion packing materials. The polyolefin co-extruded film for liquid-liquid multi-chamber infusion bags includes a heat sealing layer, an outer surface layer, and an intermediate layer. The heat sealing layer includes random copolymer polypropylene, terpolymer polypropylene, ethylene-?-olefin copolymer, and styrene block copolymer. The outer surface layer includes polypropylene and styrene block copolymer. The intermediate layer includes polypropylene and styrene block copolymer. The polyolefin co-extruded film achieves peelable seal by a two-step method and has a stable heat sealing strength, so as to prevent the accidental opening of peelable seal lines of an infusion bag and ensure smooth communication among various chambers during clinical use by extruding and opening the peelable seal lines.