Many RC frame structures were severely damaged in the Wenchuan earthquake, but the collapse rate of RC frame structures in the extreme earthquake area zone far exceeded that of multi-storey brick and concrete structures. Since September 2022, frequent earthquakes have occurred in Sichuan . It is necessary to re-explore the collapse mechanism and seismic performance. In this paper, the collapse mechanism and seismic response analysis of RC frame structures are studied by field earthquake damage and failure forms of multi-storey RC frame structures, combining numerical models and using the MIDAS Gen finite element method.The results show that the damage and yielding of the frame columns are the main factors for the RC frame collapsed, the simulation of additional infill walls,when the seismic intensity reaches 10 degrees, the inter-storey displacement angle is about 1/46, which reduces the axial compression ratio of columns, improves the damage ductility of columns, increase the limit lateral capacity of the structure, have the effect of seismic first line of defense, to avoid the overall yielding damage.