To address the issue that a single geophysical exploration technology cannot accurately locate local seepage in earth-rock dams, through combining the surface wave method and high-density electrical method to transform multi-source original exploration data into resistivity, an integrated geophysical information fusion technology was proposed using principal component analysis. A physical model experiment was conducted on a homogeneous earth-rock dam with three preset seepage hazard channels. By comparing and analyzing the localization areas of seepage channels identified by two single geophysical techniques and the integrated geophysical information fusion technology, the accuracy of seepage hazard localization of the integrated geophysical exploration technology was demonstrated, and the criteria for identifying seepage hazard areas were established. The integrated geophysical information fusion technology was applied to an earth-rock dam project with seepage problems, and the results indicate that this technology has the advantages of non-destructive detection, high efficiency, operational convenience, and clear results, and can achieve precise localization of seepage hazards.