To alleviate urban rainfall and flood disasters， promote the matching of supply and demand for rainfall and flood regulation services， and advance the high-quality development of urban and rural ecological spaces， the ecosystem service flow theory is introduced to construct a rainfall and flood safety pattern that couples the supply-demand interaction of rainfall and flood regulation services with the service flow mechanism. Taking Tongcheng County， Hubei Province as a case study， the SCS-CN model and flood risk index were used to quantify the supply and demand of rainfall and flood regulation services， respectively. Hotspot and cold-spot analyses were employed to identify ecological supply and demand source areas. Based on hydrological analysis and circuit theory， the flow paths of rainfall and flood regulation services were constructed， delineating blue-line corridors， green-line corridors， and supply-demand corridors， while key nodes were identified. The results show that the supply and demand of rainfall and flood regulation services in Tongcheng County present a significant mismatch pattern of “surplus in the southwest and northeast， deficit in the center”， with particularly prominent imbalance in the central urban area. A total of 276.15 km2 of supply source areas， 189.87 km2 of demand source areas， 391.71 km of various corridors， and 100 key ecological nodes were identified. Accordingly， an optimization plan of “Three Zones and Three Belts” was proposed to optimize the pattern by strengthening the connectivity of service flow paths and protecting key nodes； and systematic regulatory strategies were put forward from three dimensions： supply space， demand space， and service flow space. This study provides a reference for alleviating rainfall and flood disasters from the perspective of ecological space supply-demand matching. Future research can be further deepened by integrating long-term series data and multi-scenario simulations of heavy rains.