In this paper, polypyrrole films doped with phosphomolybdic acid was prepared by bulk electrolysis with coulometry in the ScCO2/Water emulsion system. The films were characterized by Raman and cyclic voltammetry methods. The polypyrrole structure was detected by Raman spectrum. And a stable oxidation-reduction behavior with three groups of peaks attributed to the phosphomolybdic acid doped in polypyrrole was established in the cyclic voltammetry curves. Moreover, the peak current was much better than that of the films prepared in conventional systems under constant pressure without the existence of ScCO2.