Due to unbalanced spatial distribution and insufficient capacity allocation of water resources in the Jinqu Basin, developing and utilizing the red bed groundwater require an effective method to address emergency water supply in this area. In this paper, geoelectric surveys employing high-density electrical resistivity tomography method were conducted to explore the geoelectric characteristics of red bed aquifer; six survey lines were arranged. The inverted resistivity profiles were validated by available borehole data and geological information. According to the notable resistivity differences between adjacent formations, the results revealed four primary geoelectric layers (Quaternary sediments, fractured siltstone aquifer, sandy conglomerate aquifer and calcareous siltstone beds) and two groundwater-storage structures (layered pore–fissure structure and vein–fault structure). Moreover, a water-rich region was delineated based on groundwater distribution and water yield of neighboring wells (> 500 m³/day). To assess further the potential of red bed groundwater, we established a hydro-geological numerical model of the water-rich region using groundwater modeling system. Aquifer permeability heterogeneity was considered by fitting the permeability coefficients collected from outcrops. The model was identified and verified by the water table at observed wells and subsequently employed to predict variation of groundwater level under different exploitation schemes. The simulation showed that short-term emergency exploitation has relatively less impact on regional groundwater environment, which demonstrates that the recovery capacity of water-rich region is good enough to cope with emergency exploitation. These findings provide important references for rational allocation and exploitation of red bed groundwater.