Abstract: Flood storage and detention areas (FSDAs) are crucial components of flood control systems in river basins. Conducting safety operation assessments of FSDAs can support decision-making regarding their activation and is of great significance for ensuring the safety of flood control in river basins. However, there is currently a lack of comprehensive safety operation analysis and evaluation systems for FSDAs. This study establishes an analytical evaluation system for the safety operation of FSDAs based on four major criteria: "effective division", "sufficient retention", "efficient discharge" and "human safety". The system is structured into three tiers: "objective—criteria—indicators," comprising 17 evaluation indicators. By referencing relevant norms and standards, and integrating practical considerations, the FSDAs are ultimately classified into three operation of FSDAs based on four major criteria: "effective division", "sufficient retention", "efficient discharge" and "human safety". The system is structured into three tiers: "objective—criteria—indicators", comprising 17 evaluation indicators. By referencing relevant norms and standards, and integrating practical considerations, the FSDAs are ultimately classified into three grades, representing "safe for use", "basically safe for use after measures taken to ensure safety", and "unsafe for use with posing significant operational risks". The proposed safety operation analysis and evaluation system was applied to 98 national FSDAs. This paper takes two typical FSDAs as examples, and the final evaluation results are "safe for use" and "basically safe for use with measures taken to ensure safety", which is consistent with empirical judgment. The results demonstrate that the evaluation indicator system possesses strong scientificity and applicability.