Abstract: Field geological survey revealed the presence of an earthquake surface rupture zone 50 km long near the Maisu fault in the northern segment of the Jinshajiang fault zone, with a maximum vertical offset of 2 m. Based on the continuous waveform data of a dense seismic array set up around the rupture zone from December 2020 to July 2022, 578 seismic events in the area of 31.55°N−31.85°N and 98.31°E−98.98°E were located by using the double-difference location method. The obtained seismic events were then analyzed using the HASH method based on P-wave initial motion to invert the focal mechanisms, and 37 focal mechanism solutions were acquired. The stress state of the study area was further analyzed by using the damped region-scale stress inversions method based on the focal mechanism solutions. The precise location results show that within the study area, there is a seismic belt 40 km long oriented WNW−ESE along the earthquake surface rupture zone, with focal depths clustered in the range of 3−10 km, and the depth profile steeply dips to the north. Moreover, there is another belt 30 km long oriented NNW−SSE, with focal depths concentrated at 3−11 km, dipping to the west. The results of focal mechanism solutions indicate that source mechanisms in this area are mostly strike-sip, accounting for 51.4% of the total. In addition, there are also a small number of reverse and normal fault mechanisms. The dominant azimuth of the P-axis of the focal mechanism solution is nearly NW−SE, which is similar to the direction of the maximum principal compressive stress σ₁ at 323°. The overall dips of the P-axes, T-axes, maximum compressive stress σ₁, and minimum compressive stress σ₃ are small, suggesting that it is under an NW-SE oriented horizontal compressive stress regime. The stress structure is strike-slip, consistent with the earthquake location and focal mechanism solution results. The stress factor （R=0.57） indicates that the maximum compressive stress σ₁, the intermediate compressive stress σ₂ and the minimum compressive stress σ₃ are basically in arithmetic progression, where σ₁ and σ₃ are determined. The WNW−ESE seismic belt exhibits dextral strike-slip with both normal and reverse components, while the NNW−SSE belt shows sinistral strike-slip, displaying conjugate fault features. It is concluded that this area has experienced at least one earthquake with M＞7.0. The near NW-SE horizontal compressive stress state is related to the intense sinistral movement of the NW−SE oriented Garze-Yushu-Xianshuihe fault zone.