Dopamine-coated silica (PDA-SiO2) was prepared by self-oxidative polymerization with dopamine and tetraethyl orthosilicate as modifying agents; Hydrophobic modified polydopamine coated nano-SiO2 (HDA-PDA-SiO2) composites were prepared by Michael addition reaction between catechol groups on the surface of PDA-SiO2 and amino groups of hexadecylamine (HDA). The composite coatings were prepared by blending HDA-PDA-SiO2 with waterborne epoxy resin. The structure and thermal properties of the composite materials were characterized using FTIR, TGA, and XPS. The effect of the amount of HDA-PDA-SiO2 (the mass percentage of the composite material in the total mass of aqueous epoxy resin and curing agent) on the physical properties of the coating samples was analyzed through physical property tests and contact angle measurements. The impact of the amount of HDA-PDA-SiO2 on the anti-corrosion performance of the coating was evaluated through electrochemical experiments and salt spray tests. The results indicate that the HDPDNS/WEP2 coating, prepared using 0.8% HDA-PDA-SiO2, exhibits the best overall performance. It has an adhesion rating of 0, a pencil hardness of 4H, an impact resistance of 45 kg cm, a contact angle of 108.8°, and a corrosion inhibition efficiency of 98.3%. Compared to the WEP coating, the corrosion current density of the HDPDNS/WEP2 coating decreases from 7.01×10-5 A/cm2 to 3.92×10-6 A/cm2, and the corrosion potential increases from-0.547 V to-0.199 V. Additionally, the HDPDNS/WEP2 coating shows no significant changes in salt spray resistance over a 30-day test period.