Frame structures are widely used in construction projects due to their cost-effectiveness and ease of construction, but they are prone to damage during long-term service and occasional loads, with early damage that is difficult to detect and can easily lead to structural safety hazards. To achieve precise identification of frame structure damage, steel frame structures are taken as the research object, the ANSYS5.0 platform is used to establish finite element models and conduct modal analysis, the B&K (Brüel & Kj?r) pulse excitation system for modal testing is combined, and the test dynamic response results are used to complete finite element model correction. On this basis, mass-dominated damage is simulated by adding additional mass blocks. The structural density is selected as the design variable. Based on the first four natural frequencies under damage conditions, the corrected model is further optimized using the rate of change of design variables as the basis for damage identification. Research results show that the ANSYS platform's inherent optimization module is suitable for frame structure damage identification, and the modal parameters of the corrected finite element model have a dynamic responsive error of less than 1% with the solid structure. The research results can provide theoretical basis and technical reference for damage monitoring and identification of similar frame structures.