Based on the characteristics of extreme water cycle, the connotation and theoretical basis of ecological prevention and control of water disasters were explained by combining frontier theories, such as Nature Enriched and Attributes Coordinated Watershed and gray-green infrastructure coordination. A new paradigm for water disaster prevention through gray-green infrastructure—a technical system integrating Three-Dimensional Diagnosis of Hydrological Distortion, Spatiotemporal Remapping of Runoff Coefficient, and Dual Control of Water Yield and Consumptive Use were proposed. Addressing the current need for transforming water disaster defense systems, it outlines practical implementation pathways including zoned and categorized implementation, intelligent management, and institutional mechanism innovation. These findings aim to provide the theoretical underpinnings and technical pathways to advance a critical shift in water disaster prevention, involving moving from an engineering-led “storage”and “dredge” mode to an ecology-first “adaptation mode”.