Patterned conductive thin films have been widely used in the field of sensors. In this study, patterned poly(3,4-ethylenedioxythiophene) (PEDOT) nanofilm with nanoporous is achieved by reverse micellar etching. Firstly, the surface of silicon dioxide wafer substrate was hydrophilized, and a quite mount of water molecules were absorbed on the surface of the substrate at a certain humidity. Then, the mixed solution of ferric chloride/PEG-PPG-PEG block copolymer/n-butanol was coated on the surface of the substrate to form an oxidant film containing reverse micellar nanospheres. Porous PEDOT films were obtained through vapor phase polymerization method (VPP). Optical microscope and scanning electron microscope were used to verify the formation mechanism of nanopore pattern, and four-point probe was used to test the electrical properties of patterned thin films. A series of conditions affecting the pattern formation, such as the concentration of PEG-PPG-PEG block copolymer and ambient humidity of silica wafer processing, were studied. The results of this study show that the increase of PEG-PPG-PEG block copolymer concentration and ambient humidity contribute to pore formation. The highest conductivity of the conductive patterned film can reach 83.68 S/cm, while its hole aperture is around 248 nm. Reverse micelle etching method can greatly increase the specific surface area of PEDOT film. Compared with other patterning methods, the method is simple in operation and low in cost, and has great application potential in biosensor, gas sensor and other fields.