The present invention relates to a high-bonding three-layer co-extruded film for steel-aluminum-plastic composite strips and a method for preparing the same. The three-layer co-extruded film comprises three layers: a layer A, a layer B, and a layer C. The layer A is in contact with the steel-aluminum strip, the layer B is an intermediate layer, and the layer C is in contact with a polyethylene (PE) sheath. The layer A comprises, by weight percentage: 40% linear low density polyethylene (LLDPE), 25% ethylene-vinyl acetate copolymer (EVA), 15% maleic anhydride grafted linear low density polyethylene, and 20% low density polyethylene (LDPE). The layer B comprises, by weight percentage: 70% linear low density polyethylene (LLDPE), 25% low density polyethylene (LDPE), and 5% bright green masterbatch. The layer C comprises, by weight percentage: 70% metallocene-based linear low density polyethylene (MLLDPE), 23% low density polyethylene (LDPE), and 7% ethylene-vinyl acetate copolymer (EVA). The layer A of the high-bonding three-layer co-extruded film for steel-aluminum-plastic composite strips is a hot-bonding layer, and the peeling strength after hot-bonding with the steel-aluminum strip can reach 8N/cm or higher.