Low-carbon steel is an important commodity material, but poor corrosion resistance has a strong impact on its service life, which leads to great loss in economic development. Polymer coatings serve as barrier layers that confer corrosion resistance. However, robust adhesion between steels and polymer films operating in complex fluids is challenging. This study evaluates the utility of adhesion layers composed of polydopamine, an organic film formed through simultaneous deposition, and polymerization in aqueous phases. Here, polydopamine serves as an intermediary adhesion layer between metallic substrates and polymer coatings. The composition, microstructure, and electrochemical properties of polydopamine nanomembranes are characterized. The impact of polydopamine nanomembranes on adhesion and supplementary corrosion resistance of polymer-based barrier layers is assessed using a functional assay. These results suggest that polydopaminebased nanomembranes can serve as effective adhesion-promoting intermediary layers that retard corrosion and prolong the service life of low-carbon steels in certain applications.