In dam leakage monitoring, due to the complexity of influencing factors, certain interference exists for data interpretation. Two groups of typical geoelectric models of dam leakage were established, and their response characteristics were analyzed by forward modeling. The combination analysis of apparent resistivity pseudo sections and inversion results can eliminate some false anomaly interference and improve the recognition of target. In the anomaly seepage monitoring of a dam, combined with the measured data and inversion results, through continuous tracking of the low resistance abnormal body, the causes of abnormal seepage and the location of the leakage passage were deduced, providing basis for engineering treatment in the next step.