The invention discloses a rainwater reuse system in a residential area, comprising a rainwater collecting device, a rainwater pumping device and a rainwater purifying device. The rainwater collectingdevice consists of a cylindrical storage tank built underground, then the rainwater on the surface can flow into the underground water storage tank through the hole on the surface, and the pump groupon the top of the surface structure can suck the rainwater into the water storage tank on the surface for secondary purification treatment and adsorption through the pumping action, and then the rainwater can be purified again by the water purifier for people to drink directly, or can be directly pressed into the underground, so as to replenish the groundwater. As that rainwater is collect, pumpedand filtered, when the water is sufficient, the collect rainwater can be purified for people to drink, and can also be pressed into the underground to replenish groundwater, thereby not only saving water resources, alleviating the pressure of municipal drainage, but also effectively replenishing the groundwater and preventing land subsidence. The method can be used not only in the flood control engineering of the residential area, but also in the urban drainage engineering.