Abstract: There were many well fields in Yuheng Mining Area (northern district) with rich coal resources, but they were threatened by water hazards. To accurately and fast discriminate water filling source of the mines, taking Balasu Well Field as an example, we research hydrogeochemical characteristics by using many methods such as complete water quality analysis, isotope test, organic detection and corrosion evaluation for all kinds of waters in this area. The results showed that, the change rules of total hydrochemical type from the surface waters to the shallow aquifer to the deep aquifer was HCO₃-Ca·Mg, HCO₃-Na, and SO₄-Na. All kinds of waters belong to the modern groundwater, sub-modern groundwater, or the mixed water of sub-modern and recent supply from shallow to deep. As the aquifer deepens, the data of TOC and UV₂₅₄ gradually decreases, and different waters showed different DOM fluorescence characteristics. With the increase of buried depth, the degree of corrosiveness of various types of water to concrete structures, steel reinforcement and steel structures is from weak to strong.