Geospatial data with attribute tables serve as the foundation for spatial analysis, data sharing and exchange, and application services on the regional scale. GIS models based on 3D spatial data have been widely applied in related fields such as urban planning, landscape management, and ecosystem monitoring. However, due to the unique 3D structure and physiological characteristics of plants, there is a lack of systematic and standardized modeling and visualization methods for 3D vegetation. This study proposed 2.5D and 3D modeling methods of 3D vegetation at the regional scale based on OGC standards and GIS platforms, including 2.5D vector models, 2.5D raster models, 3D geometric models, and 3D Billboard models. Then, by taking the Qinghai Lake Basin as a case study, different kinds of vegetation models were built and visualized to test the rapid generation and visualization of large-scale vegetation in 3D scenes and the geospatial attribute integration on the WebGIS platform. This study could provide a reference for vegetation modeling and analysis at the regional scale and offer a pathway to support public participation and collaborative sharing with intuitive 3D interactive vegetation models on the WebGIS platform.