Abstract: in order to study the migration patterns of pollutants in groundwater, this article conduct numerical simulation by taking the chloride in groundwater of a power plant as the predictor. Generalize the aquifer material composition, boundary conditions, initial conditions and source sink term of the study area, establish the hydrogeological model by GMS software, syudy migration patterns of pollutants in groundwater on the simplified hydrogeological model. Research results show that: under the condition that under the condition that contaminant discharge is simplified as a constant point source,(1) Plane migration of pollutant elliptical diffusion with the leak point as center, the long axis of pollution is the direction of groundwater flow.(2) the maximum migration distance and the pollution influence range of the pollutants both increase with time, but the rate of change continues to decrease.(3) Near the location of pollution sources, concentration of pollutants increased with time, but the concentration change rate gradually decreased. Far away from the source of pollution, concentration of pollutants increased with time, the initial concentration change rate increased with time, in the late stage, the concentration change rate decreased gradually with time.