To elucidate the dynamic evolution of pore structure characteristics in recycled aggregate concrete (RAC) under real marine exposure environments, this study integrated percolation theory with advanced micro-testing techniques, including X-ray computed tomography (X-CT), alongside macro-performance analyses. The investigation focused on the pore distribution and chloride ion corrosion in RAC modified with fly ash (FA) and metakaolin (MK) subjected to real marine exposure. The study provided a comprehensive assessment of the effect of chloride ion corrosion on the progression and development of internal pores and cracks within RAC, and examined the percolation performance across various RAC formulations and real marine exposure ages. Findings reveal that the strategic incorporation of FA and MK significantly improves RAC compressive strength and resistance to chloride ion corrosion. A discernible correlation between fractal dimension and both macro-performance and percolation parameters is established. Percolation theory effectively predicts chloride salt migration and elucidates the underlying erosion mechanisms. This research offers critical insights into ion transport mechanisms in concrete and enhances the understanding of RAC durability.