Abstract: In order to systematically identify the possible impact of hazardous waste landfill construction project on regional groundwater environment, the numerical modeling method of vertical transport of pollutants in unsaturated zone are built based on the special characteristics of hydrogeological conditions in the loess hilly region of northwest China and the factors and scenes of the groundwater environmental impacts are identified and simulated based on the landfill site layout and the possible pollution risk. The prediction results show that it will take 18~19 years for Pb and Ni to pierce through the upper aeration zone and leakage of pollutants in accident scenarios will not affect the groundwater environment in this area. On the premise of taking effective anti-seepage measures for landfill area in accordance with the relevant technical specifications, and the construction of landfill leakage detection system, the groundwater environmental protection target for site selection of this hazardous waste landfill is reachable.