NOVELTY - A composite film containing vanadium-resisting layer is used in full-vanadium liquid flow energy-storage battery. The vanadium-resisting layer includes aromatic heterocyclic polymer film, polybenzimidazole film, or polyimidazole film. The vanadium resisting layer at 110-200?C is transferred to side of the sodium type sulfonic acid base film to obtain double layer film. The obtained double layer film is placed into strong acid solution for treatment to allow acid-base crosslinking reaction between the basic group in the vanadium-resisting layer and hydrogen of sulfonic acid base film.    USE - Composite film containing vanadium-resisting layer used in full-vanadium liquid flow energy-storage battery (claimed).    ADVANTAGE - The film has low price and improved vanadium-resisting effect, which has positive effect to cost control of energy-storing battery.    DETAILED DESCRIPTION - Composite film containing vanadium-resisting layer is used in full-vanadium liquid flow energy-storage battery. The vanadium-resisting layer comprises aromatic heterocyclic polymer film, polybenzimidazole film, polyimidazole film, polyvinyl imidazole film, polypyridine film, polyvinyl pyridine film, polyethylene film, polyethylene pyrimidine film, poly-thiazole film, polybenzothiazole film, polyoxazole film, polybenzoxazole film, polyoxadiazole film, quinoline film, polyquinoxaline film, polythiazole group film, polytetrapurine film or polyimide film. The sulfonic base film is placed in sodium hydroxide (0.05-10M) until hydrogen (H+) is completely converted into sodium (Na+) to obtain sodium-type of sulfonic acid base film. The vanadium resisting layer at 110-200?C is transferred to side of the sodium type sulfonic acid base film to obtain double layer film. The obtained double layer film is placed into strong acid solution (0.1-25 mol/L) for treatment to allow acid-base crosslinking reaction between the basic group in the vanadium-resisting layer and H+ of the sulfonic acid base film to obtain the composite film.