In recent years, people around the world are living in better and better conditions, and people are demanding more and more from their environment, and pollution of the water environment has become the most serious environmental hazard. In many areas, due to the strong development of agriculture and industry, their pollutants are discharged directly into nearby river basins, leading to eutrophication of water bodies. Failure to carry out river water pollution (WP) prevention and control not only poses a major threat to the health of the people in society, but also has a serious impact on the harmonious and stable development of society. Therefore, this paper uses 3D remote sensing technology (RST) to collect images of river basins, generate remote sensing maps of river basins, extract features of remote sensing images using spectrum classification, and establish river water quality monitoring stations to obtain water quality data of each basin section. The application of spectrum classification and 3D RST provides technical support for the construction of river WP prevention and early warning system (EWS), helps to monitor the water quality in river basins and early warning WP accidents, is conducive to promoting the development of WP prevention, and improves the current crisis of river WP prevention in China.