Based on the seismic monitoring capability of the Sichuan Basin,this study analyzed historical seismicity using the earthquake catalog of the China Earthquake Networks Center,including events with M_S≥6.0 from 780 B.C. to 1969 and events with M_S≥5.0M from 1970 to 2024. the results indicate that fault zones along the basin margin have remained persistently active,whereas the basin interior is a relatively low-seismicity region. However,the frequency of M_L≥2.0 events began to increase sharply in 2015,and moderate to strong earthquakes have also become more active over the past decade. Based on the spatiotemporal characteristics of seismicity in the Sichuan Basin and the distribution of seismic clusters,the evolutionary features of seismic activity were further examined in detail for seven areas: Weiyuan-Zizhong-Rongxian,Yibin-Xuzhou,Yibin-Cuiping,Changning-Junlian-Gongxian-Xingwen,Longchang,Rongchang-Luxian,and Jiangbei in the Chongqing area. In addition,the Magnitude-Sequence-Number method,a hybrid approach combining the Goodness-of-Fit Test(GFT)and Maximum Curvature(MAXC)methods,and the sliding-window method were used to investigate temporal variations in the minimum magnitude of completeness and seismic frequency in these seven regions. the results show that seismic activity in the Weiyuan-Zizhong and Changning-Junlian-Gongxian-Xingwen regions has been the most active and relatively intense over the past decade,with significant increases in seismic frequency in 2015 and 2018,respectively. Seismic frequency peaked during 2019-2021,and most M_S≥5.0 earthquakes occurred in 2019. This pattern exhibits a strong spatiotemporal correlation with hydraulic fracturing activities associated with shale gas extraction in these two regions.