The invention discloses a method for preparing a graphene/polyaniline composite film electrode. The method comprises the following steps: adding aniline in hydrochloric acid, and stirring to obtain a product A; adding ammonium persulfate in the hydrochloric acid, and stirring to obtain a product B; mixing the product A with the product B, stirring, filtering, cleaning through distilled water and alcohol, and drying a sample obtained by filtering to obtain a product C; adding the product C in deionized water, and carrying out an ultrasonic oscillating treatment until a homogeneous polyaniline aqueous solution is obtained, namely, a product D; adding graphite oxide in the product D, and carrying out the ultrasonic oscillating treatment to obtain a product E; stewing the product E to obtain a product F; depositing the product F on a flexible plastic film, and drying to obtain a product G; soaking the product G in a hydrogen iodide solution, reducing, and cleaning to obtain a product H; soaking the product H in a hydrochloric acid solution, and drying to obtain a product I. The composite film of graphene/polyaniline fibers prepared by the method disclosed by the invention can be directly used as an electrode material of a flexible film super capacitor, and the method is simple to operate, short in time consumption, little in material consumption and is environmental friendly.