Abstract: The pollution problem of phreatic water has become increasingly prominent with the construction and development of the Northern Shaanxi Energy and Chemical Base (NSECB). In order to prevent groundwater pollution and protect water resources, on the basis of the basic data of groundwater survey, groundwater pollution investigation and tests on in-situ sewage vertical infiltration and horizontal movement in the zone of aeration in the study area, the authors selected the depth of the phreatic water level (D), precipitation recharge (R), aquifer lithology (A), soil types (S), topographic slope (T), impact of zone of aeration (I) and permeability coefficient (hydraulic conductivity) of aquifer (C) as proxies and used the DRASTIC index system to establish the phreatic water vulnerability assessment system and evaluate the vulnerability of phreatic water in the study area. Finally, according to the evaluation results, the study area is divided into the high, middle and low vulnerable districts and corresponding measures and suggestions for pollution prevention in the three districts are put forward.