Building collapse due to earthquakes constitutes a major cause of casualties. Conducting scientific and systematic seismic performance assessments of buildings before an earthquake and formulating targeted earthquake prevention and disaster reduction measures can significantly mitigate life and property losses. To achieve large-scale analysis of building seismic capacity, this study primarily utilized remote sensing imagery as the main data source. Integrating this with field surveys and building information from the First National Natural Hazard Survey, a remote sensing-assisted building update method were debeloped to analyze the structural characteristics of building entities. This method successfully achieved the updating of fundamental building information in Haiyuan County, Ningxia. Based on this updated inventory, suitable structural vulnerability models for the study area were selected, and regional seismic capacity indices were constructed. These indices enabled the quantitative assessment of the comprehensive seismic capacity of regional buildings under different seismic intensity scenarios.The results indicatde that when Haiyuan County experiences a maximum seismic intensity of X (10) on the China Seismic Intensity Scale, none of its townships achieve complete seismic resistance. Specifically, 12 townships were characterized by the collapse of a minority of buildings, while 5 townships exhibited the collapse of some buildings. This research demonstrated that the remote sensing-assisted methodology for assessing regional comprehensive building seismic capacity presented in this paper offerred a novel technical approach for applications such as seismic disaster loss assessment, risk surveying, and risk zoning.