<p>Copper is a versatile material, commonly utilized in power transmission and electronic devices, but its relative high reactivity necessitates a long-lasting protective technique. Here, we report a method that combines plasma-enhanced non-equilibrium magnetron sputtering physical vapor deposition (PEUMS-PVD) and anodization to construct a self-healing three-dimensional Ti/Al-doped TiO₂ nanotubes/Ti₃AlC₂ coating on the surface of Cu substrates. This novel strategy enhances the corrosion resistance of copper substrates in marine environments, with corrosion current densities of up to 4.5643×10⁻⁸ A/cm². Among them, the doping of nano-aluminum particles makes the coating self-healing. The mechanistic analysis of the corrosion behaviors during early immersion experiments was conducted using electrochemical noise, and revealed that during the initial stages of coating immersion, uniform corrosion predominates, with a minor occurrence of localized corrosion.</p>