To address the challenges of interregional coordination in population transfer and resettlement during catastrophic earthquakes,this study takes the Beijing-Tianjin-Hebei(BTH)region as a case study. By integrating multi-source data,including historical ground-motion records,building census data,and population census data,and adopting a scenario-based approach,a magnitude 7.8 earthquake scenario was constructed and reproduced. Through analyses of building seismic damage and differences in daytime and nighttime population distribution,the study assesses the scale of the population requiring resettlement and the corresponding demand for transfer and resettlement across the region. On this basis,it proposes an optimized collaborative organizational structure and a dual-track response process consisting of autonomous collaboration and demand-driven collaboration. the proposed three-level collaborative shelter network—core undertaking,auxiliary support,and backup supplementary—together with supporting operational guarantee mechanisms,including dynamic capacity allocation and cross-regional material scheduling,can effectively meet the diverse needs of cross-regional population transfer and resettlement. This research provides a scientific reference for improving the catastrophe response system of ultra-large urban agglomerations and enhancing regional collaborative capacity for earthquake disaster prevention and mitigation.