Reinforcement corrosion is an important factor influencing the service life of reinforced concrete structures in offshore atmospheric environment. To study the effects of concrete carbonation and chloride corrosion on reinforcement corrosion in offshore atmospheres, an engineering measurement of reinforced concrete structures with varying ages was conducted. This assessment included measurements of compressive strength, carbonation depth of concrete, surface chloride concentration, and corrosion depth of steel. Utilizing the obtained measurements and prior research findings, a relationship model between concrete carbonation depth and compressive strength was developed. Additionally, a prediction model for reinforcement corrosion depth was established, taking into account both concrete carbonation depth and the surface chloride concentration of reinforcement. Building upon these models, a damage plastic analysis of reinforced concrete frame columns with different ages and axial compression ratios was performed using Abaqus analysis software, revealing the seismic performance variation of corroded reinforced concrete frame columns concerning service age and axial compression ratio.