PIN/PAN(Polyindole/Polyacrylonitrile)films were prepared by electrospinning to replace cellulose paper(C-P)in paper-based aluminum air and applied to thin film aluminum air batteries. This study analyzed the influence of PIN content on the ionic conductivity and liquid absorption rate of thin film electrolyte. The surface morphology and chemical composition of PIN/PAN films were analyzed by SEM and FTIR. The ionic conductivity and discharge characteristics of thin film electrolyte were analyzed by electrochemical workstation and battery test system. The results show that PIN/PAN thin film electrolyte can effectively improve the performance of thin film aluminum air battery. At 3 mA cm_^-2,5 mA cm_^-2and7 mA cm_^-2, the discharge time is about 21%, 27% and 34% higher than that of paper-based aluminum air battery, and the discharge time is related to the liquid absorption rate and ionic conductivity of thin film electrolyte. The ionic conductivity of electrolyte prepared by 4% PIN/PAN film is 6.7×10_^-4 S.cm_^-1, and it has good adsorption capacity for alkaline solution. The highest liquid absorption rate is 496%,which is 3.3 times higher than that of cellulose paper.