After the water impoundment of the Three Gorges reservoir,several earthquakes above M3.5 occurred in the area adjacent to the northern end of the Xiannvshan fault,which has attracted much attention. In this study,a series of analyses were carried out on the change of Zigui dynamic water level,hydro-chemical characteristics and the GNSS deformation data. The results show that:①The rapid change of Zigui well water level is mainly affected by the change of tectonic stress in the region. In the early stage,the tensile stress is dominant,while in the later stage,the regional stress changes to the compression state. ②The characteristics of GNSS strain field show that the high value area of surface expansion rate is located around and in the south of the Three Gorges reservoir area,and the high value area is located in the north of the Xiannvshan fault. Moreover,the time series of GNSS is well synchronized with the fluctuation of Zigui well water level. ③The earthquake swarms started in early October 2020 are related to the compression state of the region and lasted for 6 months,indicating that the stress accumulation in the study area has exceeded shear strength of the rock,and caused the rock failure.