The invention discloses a rain-flood resource utilization method. The structure includes an urban rainwater utilization mode and a rural rainwater utilization mode; in the urban rainwater utilizationmode, after runoff generated by undercutting of a greenbelt in a urban development and construction area, deepening of facilities in the permeable ground, precipitation of underground water collectingfacilities is collected and stored and seeps, the runoff can be used as undrinkable water for houses, greenbelts, car wash and the ecological environment; in the rural rainwater utilization mode, through pit-ponds in plains, pools, water cellars, small reservoirs and check dams, rainwater resources are collected, stored and used for the agricultural irrigation and the rural life or groundwater supplement, The method increase the utilization amount of surface water, flood is scientifically retained, flood water resources are dispatched, the flood water resources can be directly converted intoavailable surface water resources, the available amount of rain and flood resources can be increased to 1.91 billion per square meter, and the method is of great significance to support and guaranteethe sustainable development of the national economy and the society.