<p>The Xiluodu Reservoir, situated on the lower Jinsha River, is fourth-largest hydropower in the world. The dam lies in the central part of the Leibo–Yongshan block, bounded by the Ebian–Jinyang, Lianfeng, and Mabian–Yanjin faults. Following the impoundment of the Xiluodu Reservoir in May 2013, seismic activity in the surrounding area increased markedly, and the Yongshan <i>M</i>_S5.1 and <i>M</i>_S5.2 earthquakes occurred on April 5 and August 17, 2014, respectively. In this study, we collected a high-resolution seismic catalog for the Xiluodu Reservoir region from 2010 to 2019. Using statistical parameters including the coefficient of variation (<i>C</i>_V), <i>b</i>-value, Epidemic-Type Aftershock Sequence (ETAS) model, and nearest-neighbor distance, we analyzed the spatiotemporal characteristics of post-impoundment seismicity and explored its classification. The rapid rise in the<i> b</i>-value during the early filling stage suggests that reservoir loading disturbed the local stress field, triggering a surge in microseismic events. The high consistency between the ETAS model and NND results demonstrates that reservoir-induced earthquakes in the Xiluodu Reservoir area predominantly follow the background mode and exhibit an almost unipolar distribution in spatiotemporal density plots. This phenomenon reflects the distinctive nature of the driving mechanisms underlying seismic activity in the reservoir area. The area near the dam shows a very high seismic attenuation rate and a denser background pattern, while a small proportion of earthquake events in the <i>M</i>_S5.1 and <i>M</i>_S5.2 source regions show a clustered distribution, indicating the existence of a seismic triggering mechanism here.</p>