现行隧道设计中，初期支护的安全性评价是实现隧道施工阶段初期支护动态设计的关键。为解决这一问题，基于矩阵位移法建立以关键节点位移为已知量的变形-结构法，即由关键节点的位移值直接反算结构荷载及内力，进而依据规范定量评价初期支护的安全性； 并编制相应的计算程序，依托郑万高铁香炉坪隧道进行工程应用分析。研究结果表明： 1）变形-结构法较之其他以位移为基础的反分析方法，具有原理简单、参数易选取、计算速度快等优点。2）关键节点的空间位置应尽可能均布，并应兼顾特征点，如拱顶点、跨度最大点、墙脚点等，且关键节点的数量应不小于5。考虑到施工现场的复杂性和保证结果的准确性，建议关键节点的数量取7。3）隧道施工过程中，可通过关键节点的位移监控量测数据，利用变形-结构法进行初期支护的安全性评价。

In the current tunnel design, the safety evaluation of primary support is the key to realize dynamic design of the primary support in tunnel construction. The deformationstructure method, which takes the displacement of key nodes as the known quantity, is established based on the matrix displacement method, namely, the structural load and internal force are directly calculated from the displacement value of key nodes, and then the safety of primary support is quantitatively evaluated according to the specification. The corresponding calculation program is compiled and the engineering application analysis is carried out relying on the Xiangluping Tunnel on ZhengzhouWanzhou Highspeed Railway. The results show that: (1) Compared with other inverse analysis methods based on displacement, the deformationstructure method has the advantages of simple principle, easy parameters selection and fast calculation speed. (2) The spatial location of key nodes should be uniform as much as possible, and the characteristic points should be taken into account, such as the arch point, the maximum span point, the foot of the wall point, etc., and the number of key nodes should not be less than 5; considering the complexity of the construction site and in order to ensure the accuracy of the results, it is suggested that the number of key nodes should be 7. (3) During tunnel construction, the safety evaluation of primary support can be carried out by using deformationstructure method based on the displacement monitoring data of key nodes.