Abstract: From the perspective of resilient city development, this study established a flood-control material reserve index model incorporating economic, demographic, and risk assessment indicators. The entropy weight method was employed to determine indicator weights, and a regional collaborative framework was adopted to optimize the spatial layout of flood-control material warehouses. Three trans-administrative rivers in Beijing Municipality—the Yongding River, the Beiyun River, and the Chaobai River—were selected as study areas. Based on data including regional gross domestic product(GDP), permanent resident population, and water-related disaster risk indices for riverside administrative districts in 2018 and 2023, the reserve indices and their evolutionary characteristics were quantitatively evaluated. The results indicate that the population index consistently exhibited the highest weight in the Yongding River Basin, where Fengtai District maintained the highest reserve index,increasing from 0.863 to 0.866. In the Beiyun River Basin, the economic index remained the dominant factor, with Chaoyang District reaching the highest reserve index of 0.973. In the Chaobai River Basin, the weight of the risk assessment index increased to 0.352 in 2023 and became the dominant indicator, while Tongzhou District maintained the highest reserve index,rising from 0.795 to 0.828. Based on the indicator characteristics, locational conditions, existing warehouse distribution, and historical flood impacts of each administrative district, a hierarchical collaborative structure integrating centralized reserve allocation and rapid-response forward warehouses was proposed, and corresponding optimization strategies for flood-control material warehouse layout were developed for each river basin. The findings provide scientific support for optimizing crossdistrict flood-control material warehouse allocation, improving coordinated emergency resource management, and advancing resilient city construction in megacities.