To study the corrosion resistance of the composite coating between GO and polypyrrole, a polypyrrole (PPy) coating was prepared by electrochemical polypyrrole monomer on Al sheet through potentiostatic method. The polypyrrole/reduced graphene oxide (PPy/rGO) composite coating was then formed by electroplating graphene oxide solution on the surface of the PPy coating. SEM, Raman and FTIR were used to characterize the microstructure and composition of the coating. Hydrophobicity of the coating was tested by using the contact angle measuring instrument. The corrosion resistance of the coating was analyzed by polarization curve and EIS. The results show that the rGO coating covers the defects on the surface of the PPy coating, which makes the surface of composite coating level and smooth. PPy/rGO composite coating shows good hydrophobicity than the PPy coating. The corrosion current density of the PPy/rGO composite coating is smaller than that of the PPy coating and Al, indicating that the corrosion rate is lower. Compared with the PPy coating and Al, PPy/rGO composite coating has larger impedance arc, which indicates the PPy/rGO composite coating has stronger hindrance to electrolyte ion in solution. Al and PPy coatings are corroded to different degrees, however, the PPy/rGO composite coatings has no obvious corrosion Phenomenon. Therefore, the PPy/rGO composite coating has better corrosion resistance.