Owing to the stochastic nature of sea tides, climate, and the heterogeneous properties of concrete materials, the parameters influencing structural performance exhibit both temporal and spatial variability. Current models for assessing structural durability and maintenance rely on existing detection data to evaluate structural performance and devise maintenance strategies. However, they fail to integrate real-time monitoring data on environmental actions and structural resistance into the durability assessment and maintenance analysis, leading to a certain delay in evaluation and maintenance outcomes. To address these gaps, a durability evaluation and maintenance model was proposed for marine concrete structures that incorporates updated temporal and spatial data. Environmental action data for marine concrete structures, spanning extensive time periods and multiple locations, were gathered through exposure tests. A model was developed to account for real-time variations in environmental actions and structural resistance parameters. Using the Hangzhou Bay Cross-Sea Bridge as a case study, the durability evaluation and maintenance analysis of marine concrete structures in service was conducted. The case study demonstrates that the proposed model effectively utilizes the surface chloride ion concentration and chloride ion diffusion coefficient real-time detected in the structure to update the limit state, resulting in a durability evaluation and maintenance analysis that more accurately reflects the actual durability of marine concrete structures.