The utility model discloses a be used for greenery patches inner loop purifies and retrieval and utilization rainwater structures, including overflow formula rainwater well I, purification tank II andreservoir III. Wherein purification tank II is formed by biology delay facility and the combination of filtration facility two parts, and the setting of biological delay facility is on purification tank II upper portion, and the filtration facility sets up in purification tank II lower part, sets up concrete baffle between the two. Be detained rainwater after facility and the primary purificationof filtration facility by the biology and flow in reservoir III, carry out the manifold cycles purification to biological delay facility by the rainwater transferred of water pump in with reservoir III, export the retrieval and utilization with the rainwater at last. These structures can improve retrieval and utilization rainwater quality, increase retrieval and utilization amount of rainfall. Itthe retrieval and utilization rainwater technique of an ecology, economy, energy -conservation and environmental protection.