首先介绍了既有线路三维设计模型的建立理论及实现方法。通过分析它们存在的困难和不足 ,提出了一种利用航测或外业勘测地形数据 ,在微机上建立设计线路行经地区的三维地形模型以及利用平、纵、横设计数据 ,建立三维线路模型 ,采用三维图形覆盖技术达到构建三维地形及线路整体模型的一种方法 Firstly, the establishment theory and realization method of the existing three-dimensional design model of line are introduced. By analyzing their existing difficulties and shortcomings, this paper presents a three-dimensional terrain model using aerial survey or field survey topographic data to establish a three-dimensional terrain model of the design line passing through the area and the use of flat, vertical and horizontal design data to establish a three-dimensional line model, using Three-dimensional graphics coverage technology to achieve the construction of three-dimensional terrain and a line of the overall model of a method