The paper discusses the development of the Optimization Design CAD System in the Reconstruction of the existing line, such as the system structure, critical techniques, integrated envirnment, functions, developing plan and implementation.

• 介绍既有线改建纵断面设计优化cad系统的开发情况，主要包括系统结构、块设计、键技术、成环境、能和开发规划及其实现。