A gas barrier composite film is provided. The gas barrier composite film includes a substrate layer; a functional layer disposed on one or two sides of the substrate layer, wherein the functional layer includes a first copolymer of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, or a second copolymer of acrylic acid and vinylidene dichloride, and an inorganic stack layer disposed on the functional layer.