The invention discloses a curling-resistant treatment technology for a multi-layer coextrusion film. Two surface layers of the multi-layer coextrusion film are a nylon surface layer and a heat-seal surface layer. The curling-resistant treatment comprises steps of water bath, water-removing and cooling, rolling and curing. A water bath temperature is 45-65 DEG C, a film speed is 50-80 m/min, and afilm tension is 140-250 N. The curing step is that a film roll prepared by the steps of water bath, water-removing and cooling, and rolling is statically placed for a period of time in normal pressureand temperature. The curling-resistant treatment technology for the multi-layer coextrusion film is capable of using a feature that the toughness of nylon is increased after water absorption, and using a water bath method to perform heat treatment on the multi-layer coextrusion film with the nylon surface layer and the heat-seal surface layer. While the nylon layer in the multi-layer coextrusionfilm absorbs water, heat promotes an internal stress between the layers of the coextrusion film to be released. The flatness of the film after the water bath treatment is improved, and mechanical strength, such as the toughness, is not apparently changed compared with the mechanical strength before the water bath treatment.