It is very important to quantify the damage degree of the components in the seismic-damaged structure according to the reasonable damage physical quantity，and to guide the rapid repair of the seismic-damaged structure，so as to improve the seismic performance of the structure to meet the use requirements. In view of the fact such as the measurable information of the actual seismic-damaged structure is limited，the damage degree is difficult to quantify，the process of repair and reinforcement is difficult to simulate，and the performance of the structure after repair and reinforcement is difficult to evaluate，the relationship between the end curvature of the beam and column component and the top displacement is established，and the relationship among the residual displacement，displacement，curvature and damage index is clarified. The method and process of simulating the repair and reinforcement of the component in the finite element are proposed. According to the different physical quantity of damage，the method of quantifying the damage of components is proposed. In addition，according to different damage physical quantity and repair strategy，a five-story reinforced concrete seismic-damaged structure is quickly repaired，and the seismic performance of the repaired structure is evaluated，then the seismic vulnerability is analyzed. The results show that the rapid repair of structures damaged by earthquake can effectively reduce the risk of serious damage and collapse in earthquake. The seismic performance of the structure can be maximally improved by quantifying the damage of the component according to the residual displacement drift and guiding the rapid repair of the structure. Among the two strategies of layer selection and part selection，the former has better repair effect.