通过开发工作站环境下ＣＡＤ集成软件的优化计算功能，对凹底平车建立了结构分析模型，将结构分析模型定义为一个设计，进行了静力优化、模态分析、动态优化。减轻了自重，改善了其动态特性。为凹底平车在静态、动态工况下的轻量化设计提供了理论资料。 Through the development of CAD software in the environment of workstation, a structural analysis model is established for the concave flat car. The structural analysis model is defined as a design, and the static optimization, modal analysis and dynamic optimization are carried out. Reduce weight, improve its dynamic characteristics. For the concave flat car in static, dynamic conditions of the lightweight design provides a theoretical information.