In this paper, the bonding strength and chloride ion concentration of coatings were tested on the surface-coated concrete specimens exposed for 10 years and the solid structure of Qingdao Jiaozhou Bay Bridge. The long-term protective effect of the coatings applied to the concrete structure was studied. The results show that after 10 years exposure to the frozen seawater environment, the bonding strength of the coatings on the concrete in the atmospheric zone, the splash zone and the tidal zone all exceed 1.5 MPa, which still meets the requirements of current specifications. Compared with the tidal zone, the coatings on the marine concrete exposed in the splash zone and the atmospheric zone show better long-term protection. In the tidal zone, the apparent chloride ion diffusion coefficient of the coated concrete specimens is not significantly different from that of uncoated concrete. The surface chloride ion concentration of the coated concrete in the structure of the bridge is 2.3 to 3.9 times lower than that of the uncoated concrete, and the long-term chloride ion corrosion resistance of the coatings on the bridge is slightly weaker than that of the small-sized concrete specimens.