Abstract: Taking Hulusu Coal Mine as an example, a groundwater numerical simulation model was set up by using Modflow to research the influence of chemical industry solid wastes from the mine underground backfilling on ground water environment, and the model was recognized and validated. The groundwater numerical simulation model and the solute transport model were coupled to predict the laws of contaminants transporting and three main conclusions were drawn down in this research as follows: the pollutant of the fine particles generated during coal combustion exceeded the standard value only in 2-1 coal seam, and the maximum faster distance beyond the standard value is 14.31 m, which will not cause the pollution of the mine water; considering the safety assurance, it is suggested to reserve 30 m protective coal pillar before backfilling. The chemical industry solid wastes backfill in mine can solve the problem of the land occupation, reduce the risk of environment pollution, reuse the solid wastes and save cost.