The invention provides a method for preparing a nanometer porous polypyrrole film by using nano-bubble as a template, which belongs to the technical field of material preparation. The method comprises the following steps: polymerizing pyrrole into a polypyrrole film by using nanometer hydrogen bubbles generated by electrochemistry as the template; taking out the polypyrrole film from polymerized solution after the polypyrrole film is shaped; and removing the bubble template after the nanometer hydrogen bubbles automatically escape so as to produce the nanometer porous polypyrrole film. The method simplifies the steps of removing the template by solvent during the prior preparation process by template method, and avoids the effect of the solvent on the property of the polypyrrole. The method is suitable for preparing the nanometer porous polypyrrole film which can be used for preparing electronic devices, drivers, sensors, ultrafiltration films and the like.