Abstract: The mixed soil and rock structure is an important form of seepage control in reservoir dams, but the combination of bulk fill materials and adjacent buildings is often the area of potential problems, among which leakage in the contact zone of reservoir dams is the most common and difficult to diagnose. In order to investigate the feasibility of the parallel electrical method in detecting leakage in the contact zone and the rock base of the two dam shoulders, a physical model of the leakage channel of the dam shoulders was constructed, and the AM acquisition method of the parallel electrical method was used to obtain the apparent resistivity and inverse resistivity profiles. The results of the study show that the images obtained from the inversion of the data collected by the parallel electrical technique can better reflect the leakage channel location set by the model, but due to the heterogeneous structure of the reservoir shoulder geotechnical body, the apparent resistivity profile is not very sensitive to the low resistance area of the dam shoulder, and the inverse resistivity profile still has a high volume effect. The results of leakage detection at the shoulder of Qingshan Reservoir are consistent with the results of the drilling verification, which indicates that the parallel electrical method can provide a new technical means to investigate the potential leakage of the dam abutment.