Abstract: This paper investigates a red mud reservoir in Zhangdian District, Zibo City, utilizing electrical resistivity tomography（ERT） to systematically assess concealed disaster-causing factors and stability of the red mud dam. Measurement profiles are deployed using the Wenner array, and the electrical properties of the dam body and surrounding strata are analyzed through inversion of geophysical data integrated with geological information, enabling identification of unfavorable geological structures. The findings demonstrate that the apparent resistivity values of the red mud dam are generally low, with smooth contour lines, reflecting a stable dam structure free of weak layers or fracture zones. Additionally, the deep bedrock in the reservoir area is intact, with no significant fault fractures detected. ERT effectively reveals the electrical distribution of the dam, offering a reliable geophysical basis for stability assessment. This research can serve as a reference for safety hazard detection in similar tailings reservoirs.