In this study, a neutral salt spray test method was employed to evaluate the corrosion resistance of various coatings in a simulated marine atmospheric environment. The coatings’ performance after salt spray exposure was assessed through macroscopic morphology analysis, gloss measurement, adhesion testing, hardness testing, and electrochemical impedance spectroscopy (EIS). Key performance indicators were identified using Spearman correlation analysis. The results demonstrate that solvent-based coatings exhibited superior protective properties under simulated marine atmospheric conditions. The hardness, adhesion, and impedance values of the four coatings showed a consistent decline over time, serving as reliable indicators for coating failure. However, the correlation between gloss retention and time exhibited anisotropy, varying with the type of coating. Based on the experimental findings, critical performance thresholds for different types of coatings during salt spray exposure were identified. This study provides a theoretical foundation for the future development of more efficient environmentally friendly anti-corrosion coatings.