In this study, a mechanically durable resin-based superhydrophobic coating with excellent anti-corrosion, water-repellency, self-cleaning, and anti-reflection properties was fabricated on the Al alloy substrates. The resin-based superhydrophobic coating comprised the polymethyl methacrylate (PMMA) and SiO2 nanoparticles on the anodized Al alloy substrates. The interface between the anodized Al alloy substrates and the superhydrophobic coating was strengthened by linking the rhodamine B (RhB) molecule in Al2O3 and PMMA. The RhB molecule was implanted in the Al2O3 by dissolving the RhB into the electrolyte for the anodization process. Moreover, the porous structure of Al2O3 was also improved significantly due to the existence of RhB. The bonding of N in RhB and Al in Al2O3 enhances the interface contacting of substrate and RhB, and the bonding of carboxyl in RhB and ester group in PMMA enhances the interface contacting of substrate and PMMA coating. As anticipated, the Al2O3-RhB/PMMA-SiO2 composite coating on Al alloy demonstrates significantly enhanced adhesive ability than that of Al alloy with Al2O3/PMMA-SiO2 coating. This interface-strengthening method provides a universal strategy to fabricate mechanically durable protective coating on metallic substrates.