Abstract: In view of the serious pollution problem that coal gangue precipitation leaches to groundwater, this paper intends to report the coal gangue leaching experiments in saturation state by experimental simulation method in an abandoned coal mine in Shiguai District of Bao Tou. The results show that:Ca, Mg, Fe, Cu, Zn, NO₃^-, SO₄^2-, Cl^- of coal gangue follow the basic law that concentration first increases and then decreasesa to a steady value. But the leaching rate of NO₃^-, SO₄^2-, Cl^- is significantly greater than the heavy metal leaching rate, Ca and Mg, SO₄^2- and Cl^-, Pb and Cr, Cd have similar leaching mechanism. The strongest leaching rate of heavy metal from big to small order is:Mg>Cd>Ca>Cu>Zn>Cr>Fe>Pb, content of Hg、As is very low and not detected.