The oblique photogrammetry technology has the advantages of wide application range and high precision,and can be used for high performance mapping data processing in complex scenes,which plays an important role in improving the quality of hydraulic engineering surveying results.In this paper,the technical content of oblique photogrammetry is briefly outlined,the application advantages of oblique photogrammetry in hydraulic engineering surveying and mapping are analyzed,and the specific application of oblique photogrammetry in hydraulic engineering surveying and mapping is deeply explored from five aspects of project overview,data collection,data processing,accuracy analysis and model construction.The results show that obligue photogrammetry can effectively improve the overall level of mapping and mapping quality of water conservancy projects in China.