Abstract: By extending the experimental mode, the deformation reconstruction is carried out with the idea of modal method. The local correspondence (LC) principle is used for the numerical simulation and experimental verification of the reconstruction. Firstly, the displacement mode shape data of finite number of measuring points are obtained through the experimental modal test, the accurate finite element model is established and the modal data are extracted. Then, using LC principle, the optimal finite element displacement mode shape cluster is selected to expand the measured experimental modes step by step. At last, the expanded experimental modes are used for reconstruction. Comparing the reconstruction results with the results of system equivalent reduction expansion process (SEREP) method and modal method shows that this method can significantly reduce the influence of experimental modal test error on the reconstruction accuracy and improve the reconstruction accuracy when the finite element model is accurate.