［Objective］ To address the erosion damage and poor interfacial adhesion betweenprotective coatings and concrete substrates for underwater concrete structures，a wet-curable concrete protective coating containing catechol groups was prepared based on the biomimetic mussel adhesionprinciple.［Methods］Epoxy resin（EP）was modified with nano-zirconium dioxide particles（ZrO₂）. Dopamine hydrochloride（DA）was then crosslinked with aminopropyl polydimethylsiloxane（PDMAS）. Subsequently，a catechol-containing epoxy coating（ZrO₂/EP/D-PDMAS）was prepared via sequential interpenetrating polymer network（IPN）technology. The molecular structure and microstructure of thecoating were characterized by Fourier transform infrared spectroscopy（FT-IR）and scanning electron microscopy（SEM）. The effect of DA content on the comprehensive performance of the coating was investigated through tests of adhesion strength，corrosion resistance，and mechanical properties.
［Results］The results showed that the ZrO₂/EP/D-PDMAS coating exhibited optimal comprehensiveperformance at a DA content of 4wt% . It achieved an adhesion strength of 4. 59 MPa on concretesurfaces in underwater environments，representing a 117. 54% increase compared with the ZrO₂/EP coating. Moreover，relative to the pure EP coating，the corrosion current density of the ZrO2/EP/D-PDMAS coating reduced from 4. 914×10^-7 A/cm² to 4. 393×10^-8 A/cm²，and the corrosion potential positively shifted from -0. 709 V to -0. 597 V.［Conclusion］ The ZrO2/EP/D-PDMAS coatingeffectively resolved the insufficient interfacial bonding strength of underwater concrete coatings throughthe biomimetic adhesion effect of catechol groups. With its simple synthesis process，low raw material cost，excellent interfacial adhesion and corrosion resistance，this coating significantly enhanced the protection of concrete substrates.