In order to identify the damage location and extent of the cantilever structure, a flexible damage identification method was proposed based on point spectral correlation function. According to the characteristics of the cantilever structure and the structural dynamic equation, the relational equation between the modal parameters and the structural member physical parameters was found by the transition of the flexibility matrix elements. Based on the free vibration signal of structure, the square root value of point spectrum correlation function was discussed and used as a replace of structure modal parameter. Then the damage equation of the square root value of point spectrum and the stiffness damage coefficient was established. The location and degree of single or multiple structure damage could be able to identify through solving the damage equation. This method has clear physical meaning and the unload excitation is easy to implement, and it could be helpful for applications without contrast test before and after damage. Finally, the effectiveness of the proposed method was verified through two numerical examples.
