提出了一种适合于悬索结构空间非线性分析的三节点等参数索单元有限元模型．在三维整体坐标下，由应变的定义得到了可以考虑任意高阶位移影响的非线性应变几何关系．采用Ｌａｇｒａｎｇｉａｎ坐标描述法，并由虚功原理建立了非线性有限元增量方程及切线刚度矩阵．算例计算表明，本文方法可用于各种悬索结构的计算分析． A three-node isoparametric element finite element model suitable for the nonlinear analysis of cable structure space is proposed. In the three-dimensional global coordinates, the nonlinear strain relations that can consider the influence of arbitrary higher-order displacements are obtained from the definition of strain. Using Lagrangian coordinate description method, the nonlinear finite element incremental equation and tangent stiffness matrix are established by the principle of virtual work. The example calculation shows that this method can be used to calculate and analyze various cable structures.