This paper introduces the outline of the railway route design in the three-dimensional stereo model by the railway route design principle and methods based on seamless stereo orthoimage database in MicroStation. The main work is the route design. Then the visualization of the railway route can be done according to the terrain analysis of Geopak and the senior modeling function of MicroStation. The main works are as follows: 1. The method of traditional railway route design is analyzed. 2. The main principle, technique and outline of the plane, longitudinal section and cross section design are analyzed based on seamless stereo orthoimage database. 3. The flow of the railway route design are investigated based on the seamless stereo orthoimage. The characteristics of the stereo geometry model of the seamless stereo orthoimage database can be presented asgeometry-rectified, y-parallax-free, geo-referenced accurate measurement and so on. It can be easily integrated into GIS,
so the 3D measurement, design and analysis can be done by the model. The railway design can be carried on in a three-dimensional visualization and area survey seamless environment. MicroStation has better character of 3D-modeling, visualization and expansibility. The design process and result can be visualized. Geopak runs on
MicroStation, and is integrated into MicroStation entirely. So it supports general interactive design and visualization. All-sided solving scheme is supported for the road design of the plane, longitudinal section and cross section in the Site module.