Taking a tailing pond in Hezuo of Gansu Province as study area, this paper established a groundwater flow model and a solute transport model by using Visual MODFLOW, and simulated the migration situations of 4 kinds of pollutants under 2 non-normal conditions. One condition is that the tailing pond takes no measures to prevent infiltration, while the other is that the impermeable layer is damaged. The numerical simulation predicts the reach, excessive range and maximum migration distance of the pollutants.The result showed that the contaminants mainly transport along the flow direction, and effect of pollutants on water environment is gradually increasing with time. The impacts of ammonia and total phosphorus on water environment prove to be greater while that of total arsenic and hexavalent chromium is smaller.By comparing the migration features of contaminants under two abnormal conditions, the influence of tailing pond on water environment with absence of impervious layer is worse.