According to the problem of insufficient positioning accuracy and quantitative analysis in the process of structural damage identification， this paper proposes a damage identification method based on the combination of structural vibration response-based Modal Strain Energy Change Rate （MSECR） and optimization technology. Firstly， a two-step method is used to determine the suspicious damage unit and quantitatively analyze its damage degree. The finite element method is applied to establish the damage characteristic model of the structure， and the element modal strain energy change rate index is used to construct the objective function of the damage index optimization analysis. In the process of numerical analysis， Particle Swarm Optimization Algorithm （PSOA） and Genetic Algorithm （GA） are used to optimize the design variables. At the same time， the quantitative analysis effect and identification efficiency of the damage location of the two methods of modal strain energy change rate and wavelet analysis are compared. In actual calculation examples， the beam structures are used to verify the results of the damage identification optimization method. The results show that this method can significantly improve the effectiveness of structural vibration damage and positioning. This method can not only perform quantitative analysis of structural damage quickly and accurately， but also has a better positioning effect than the wavelet method. And it can improve the identification efficiency of quantitative analysis. However， it is also found that the positioning accuracy of this method in the implementation process is easily affected by noise. The optimization of the objective function can improve the anti-noise ability of the structural damage identification method to a certain extent. The research of this method will provide certain technical guarantee for the practical engineering application of the damage identification algorithm in the future railway intelligent operation and maintenance.