Abstract: Determining the surface rupture zone of the 1668 Tancheng great earthquake is of great significance for evaluating seismic parameters and regional seismic hazards. The seismogenic fault of this earthquake is the Anqiu-Juxian segment of the Tanlu fault zone, but the southern extent of its surface rupture zone has long been disputed. The core controversy is whether the rupture continued southward across the stepover area of Yaoshang Village, Tancheng County. This study focuses on the Maipo area, located south of the Yaoshang stepover, and employs high-resolution remote sensing image interpretation, unmanned aerial vehicle （UAV） photogrammetry, and detailed geological fieldwork to identify the faulted microgeomorphic features along the northern and southern sections of the Maipo area. The geometric distribution of recent fault activity and the coseismic offset characteristics in this region are clarified. The results reveal typical strike-slip surface ruptures in the Maipo area, including fault scarps, sag ponds, and earthquake bulges, with right-lateral horizontal offsets of 2.0–5.5 m and vertical component of 0.25−1.3 m. Based on regional historical earthquake records and Quaternary dating results, these surface ruptures are interpreted as products of the 1668 Tancheng great earthquake. Integrated geological evidence and the distribution of seismic activity confirm that the surface rupture zone of this earthquake extends southward to the Maipo-Hezhuang area, with a total length of at least 153 km, rather than the previously proposed 130 km. Using empirical relationships between rupture length and rupture area, the moment magnitude of this earthquake is reassessed to be M_W7.7. These findings clarify the southern extent of the surface rupture zone of the Tancheng great earthquake, refine its magnitude estimates, and provide critical tectonic geological constraints for assessing future seismic hazards in areas such as Xinyi City, located in the southern segment of the Tanlu fault zone.