Lithium battery flexible packaging film and preparation method thereof

The invention discloses a lithium battery flexible package film and a preparation method thereof, and the preparation method comprises the following steps: (1) providing an aluminum foil, carrying out double-sided passivation on the aluminum foil, and then drying for later use; (2) a double-glue-groove net is provided, the double-glue-groove net is provided with a first glue groove and a second glue groove, one of the first glue groove and the second glue groove is filled with double-component polyurethane glue, and the other one of the first glue groove and the second glue groove is filled with modified polyolefin resin glue; (3) the aluminum foil passes through a double-glue-groove net, double-face gluing is conducted on the two faces of the aluminum foil through the double-glue-groove net, and then drying is conducted; and (4) synchronously compounding one side of the nylon film facing the bi-component polyurethane glue and one side of the polypropylene film facing the modified polyolefin resin glue on two