As the first railway project crossing the Himalayas in the world, the construction of the China-Nepal railway is confronted with many environmental and geological problems such as high elevation, a big difference in elevation, alpine climate, seismic activity zones, soft-rock deformation, and geological disasters. Since the design and selection of route schemes of the railway line are notably restricted by geological conditions, it is necessary to thoroughly understand various geological problems in the study area. This study gives full play to the remote sensing technique to overcome the limitations of surface surveys, reduce the workload of field surveys, and improve work efficiency. Based on the analyses of existing data on basic geology, engineering geology, and geological environment, this study uses the multi-source remote sensing technique to conduct a detailed interpretation and analysis of the adverse geological elements in the study area, including terrain, landform, stratigraphic lithology, geological structures, hydrogeology, landslides, debris flow, and wind-blown sand. In this way, it provides detailed, comprehensive, and reliable remote sensing data for the engineering geological survey and the route design and selection of the China-Nepal railway and plays an important role in technical support.