The bilayer film of polyaniline (PAn) composite positive/polymer electrolyte was prepared employing PAn powder as an active material and plasticized PEO-LiClO4 with the ethylene carbonate (EC) and propylene carbonate (PC) plasticizer as an electrolyte. The micro-morphology and interfacial microstructure of the composite bilayer film were observed by scanning electron microscope (SEM). The effect of the content of polymer electrolyte on the homogeneity of the PAn composite positive film and the interfacial electrochemical kinetic parameters, the utilization ratio of the active material and discharge capacity were investigated. It was found that the contacting surface area between the PAn powder and the polymer electrolyte was greatly augmented by using polymer electrolyte as a binder. The PAn composite film with gel PEO-based polymer electrolyte (GPE) as the binder exhibited better interfacial compatibility, electrochemical reversibility than the PAn positive film with poly(tetrafluoroethylene) (PTFE) as the binder, and so the utilization ratio of the active material and the high rate discharge ability were observably improved.