索穹顶结构是发展和推广 Fuller张拉整体结构思想后唯一实现的一种新型大跨空间结构 ,它的几何构造分析是一项非常重要的工作。本文在对一般空间杆件体系的分类、自应力模态和机构位移模态研究的基础上 ,从索穹顶结构特有的杆件拓扑关系入手 ,提出了单位整体可行预应力这一新概念 ,并最终解决了多自应力模态下该体系稳定性判定问题 ;通过对若干类型索穹顶结构的几何构造分析 ,得出了一些对结构设计有用的结论 Cable dome structure is a new type of large-span space structure that is the only one that Fuller can achieve when it develops and popularizes Fuller’s tension structure. Its geometric structure analysis is a very important task. Based on the research on the classification, self-stress mode and mechanism displacement modal of general space rod system, this paper starts with the topological relations of the dome-structure-specific rods and puts forward a new concept of perfecting prestress of unit Finally, the problem of determining the stability of the system under multi-self-stress mode is solved. Based on the geometric structure analysis of several types of cable domes, some useful conclusions about structural design are obtained