Heilongtan spring is the lifeblood of Lijiang Dayan ancient city, the world cultural heritage. The blackout of Heilongtan springs not only affects the landscape water of Lijiang ancient city, but also affects the image of Lijiang as a whole, threatening the protection of Lijiang's “three World Heritages”, endangering the protection of Lijiang's urban water supply source, and seriously affecting the safety of industrial and agricultural production water in downstream areas. In this paper, the principle of groundwater retention system is used to fit the detention flow and groundwater level, and the dynamic error correction is compared and selected for multiple schemes. After considering the error elimination section, there is a good correlation between the groundwater level and groundwater retention, which provides strong support for the diversion analysis of “Lijiang Heilongtan Baoquan black and white water river diversion jiuzihai ecological water replenishment project”.