The construction of three-dimensional digital city is an important application area of GIS technology, and construction of large scale city 3D building scene based on 2D building outline is a method to construct three-dimensional digital scene. This article makes a study of using ArcSDE to store the Shape files in SQL Server database, and then uses ArcObject to program the ArcSDE in order to gain the building vector polygon outline. According to people's habit observing objects, three-dimension of GIS platform follows the order from top to bottom to read vector files and then renders 3D building model. This article discusses the pyramid vector storage and management methods, and designs an interactive, fast and efficient frame to construct the large scale city 3D building scene. At the same time, it makes a detailed discussion of the process for data storage, SDE connection, data selection, data extraction, data output and data show. This method is used in "ChinaStar", the three-dimensional visualization engine. The experiment reveals that the method can conveniently and quickly construct large scale city 3D building scene.