There are some problems in the application of pipeline engineering, such as low efficiency of automatic modeling of three-dimensional graphics and difficult integration of multi-source data. Based on Cesium open source engine, this paper studies the key methods of BIM+GIS multi-source data creation, fusion and application. The automatic modeling based on the current pipeline and geological survey data, UAV oblique photography and real scene model creation, as well as multi-source data preprocessing and lightweight scheme are formed. The BIM + GIS digital platform is further developed by combining the project information viewing and interactive requirements to customize the development function module. The solution proposed in this study has been applied and verified in the raw water pipeline project of Changsha Leifeng water plant.