The invention discloses a corrosion prevention method for metal. The corrosion prevention method comprises the steps of 1, preparing conductive polymeric material; 2, connecting the conductive polymeric material to the metal through metal wires; in the step 1, conductive polymeric material monomers-aqueous solutions and dopants-aqueous solution are added into a container and stirred uniformly, oxidizing agents-aqueous solution are added in drops in the stirring process, the mixtures are stirred continuously at 0-5 DEG C for 3-5 hours and then filtered, and filter cakes are sequentially and repeatedly washed by absolute ethyl alcohol and distilled water until filtering liquid is colorless and then are dried at 60-80 DEG C for 15-30 hours; the filter cakes are pressed for forming first conductive polymeric material at the condition of 8-15 MPa. The corrosion prevention method is simple and practicable, the metal can be protected before corrosion, corrosion of the metal can be prevented or slowed down, and the corrosion prevention rate of the metal can be higher than 85%.