Abstract: In order to study the source and formation mechanism of high fluorine groundwater in buertai coal mine, the characteristics and distribution law of f-mass concentration in high fluorine groundwater are studied by means of mathematical statistics and ion analysis in the aspects of mineral dissolution and precipitation, evaporation and concentration, ion exchange and competitive adsorption. The results show that the range of C (F -) in groundwater of buertai coal mine is 0.31-11.15mg/l, and the average value is 1.7mg/l. In terms of spatial distribution, high fluorine groundwater is mainly distributed in the range of 1-5mg / L, accounting for 48.48% of the total samples; In terms of vertical distribution, high fluorine groundwater is mainly distributed in Jurassic aquifer group. The main recharge sources of water in high fluorine goaf are Quaternary and tertiary pore water and Jurassic pore and fissure water. The dissolution of fluorine-containing minerals is the main control factor of high fluorine groundwater. Ca2 + has a strong ion exchange reaction with Na + and K + in the solid phase, and the competitive adsorption of HCO3 - replaces F - adsorbed on the surface of clay minerals, promoting the enrichment of F -.