A noble, safe and electrochemically stable microporous IL-CNTs-PANI polymer electrolyte has been reported. In the microporous polymer electrolyte (MPE), polyvinylidene fluoride (PVDF) was doped with an ionic liquid (IL), carbon nanotubes (CNTs) and polyaniline (PANI). The surface structure and element composition of MPE film were measured by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and fourier-transform infrared spectroscopy (FTIR). The thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) have carried out to characterize electrolytes’ thermal stability, and the electrochemical performance was measured by cyclic voltammetry (CV) and Tafel curves. It is found that a soft and porous MPE film can be obtained by changing the content of CNTs/PANI and the heat treatment temperature. Doping with different amounts of PANI has certain effects on the thermal stability and crystallization properties of MPE film. The prepared electrolyte membrane has good capacitance, wide electrochemical window (~3 V), certain charge transfer and ionic conductivity. Finally, the prepared electrolyte membrane was used to print a NO2 gas sensor, which proved that the MPE has the potential to become a gas-sensing material for NO2 sensors.