In order to quickly and accurately find the reservoir dam leakage location, geological, geophysical comprehensive analysis method was proposed. Working area field investigation was made to investigate dam technology, formation lithology and structure. Key area dam serious leakage was deeply analyzed to build water channel; In combination with geological analysis of the survey results, using the comprehensive geophysical prospecting method investigated reservoir dam leakage. The result showed that comprehensive geophysical prospecting methods surveying was more accurate in reservoir dam leakage; On the basis of geological survey, building the dam ground fissures leakage passage greatly shortened the geophysical exploration time, simplified the geophysical exploration construction difficulty and reduced the uncertainty of geophysical exploration interpretation ambiguity.