Abstract: 3D visualization technology has been widely used in dam safety monitoring, quality inspection of water conservancy engineering, water resources allocation and other fields. Based on the application results in other fields, the 3D display and query system of water conservancy information in Poyang Lake was constructed by using 3D visualization and other technologies. So 3D terrain information display of Poyang Lake under different water levels was realized, and the virtual scene of water conservancy information in Poyang Lake was reproduced. In addition, the spatial database and multimedia database of Poyang Lake were constructed by using Java for secondary development, and the functions of visual and clear browsing and display of 3D scene in the lake area, as well as dynamic query and roaming of special water conservancy hot spot data were realized. The establishment of this system can facilitate users to fully understand the water resources, water ecology, water environment and water conservancy projects of nature reserves and scenic spots and flooded areas under different water levels in Poyang Lake area, and help to improve the scientific decision-making level of Poyang Lake managers.