["Transactions in GIS, Volume 30, Issue 5, August 2026. ", "\nABSTRACT\nThe configuration of urban low‐altitude vertiports directly influences the efficiency and convenience of urban air mobility (UAM) transportation. This study aims to optimize the urban low‐altitude VTOL vector network (VVN) by integrating urban commuting and air–ground intermodal transportation. This study develops a data‐driven framework for city‐scale eVTOL aircraft vector network planning by integrating multi‐source geospatial data, mobile signaling‐based crowd OD flows, and an air–ground intermodal location model. Building on existing network design formulations, this study uses crowd OD flows rather than individual trips as the unit of analysis. More importantly, it proposes a pruning‐and‐reduction strategy that makes the resulting mixed‐integer optimization computationally tractable with massive amounts of observed OD data. The empirical analysis takes Nanjing, a first‐tier city in China, as the research area, integrating multi‐source large‐scale geospatial data, especially mobile signaling origin–destination (OD) flow data. The experimental results show that the pruning strategy reduces the variable scale by 99.79% while preserving the near‐equivalent solution quality. The optimized VVN layout significantly improves long‐distance trip service accessibility and overall benefits. With respect to air–ground intermodal trips, the flight segment accounts for approximately 16% of the total travel time, whereas the first and last‐mile connection times account for 84%. Therefore, it is necessary to optimize accessibility between residential communities and vertiport stations, improve interconnections for ground transportation, and enhance the construction of parking facilities at vertiports. This study implements data‐driven modeling by fusing multi‐source spatiotemporal data and coupling air–ground intermodal trip transfer/connection decisions, providing methodological references for optimizing VVN location selection in multi‐modal transportation coordination.\n"]