Abstract: Using the waveform data of the 2022 Luding M_S6.8 earthquake sequence recorded by the mobile stations and the regional permanent network deployed by Sichuan Earthquake Agency, we performed computational analysis on S-wave splitting of local earthquakes, and investigated the spatial distribution and temporal evolution characteristics of upper crustal anisotropy parameters at each station, along with the spatiotemporal variations in fast S-wave polarization direction and slow S-wave time delay. The results show that the spatial distribution of the fast wave direction and time delay exhibits obvious zoning characteristics and a certain trend change over time, implying that the upper crust anisotropy is controlled by both spatial location and time-dependent stress field. On the Xianshuihe fault zone, the fast wave polarization directions of the stations such as L5512, XXXJ and LDXX are all NW−SE, which is consistent with the strike of the Xianshuihe fault zone, indicating that the main compressive stress field and fault structure in the region may act together on the crustal anisotropy. At the same time, the fast wave direction of the stations AJW, NTW and L5137 located near the Daduhe fault zone is NE−SW, which is consistent with the strike of the Daduhe fault zone, indicating the significant impact of the fault structure on the anisotropy of the upper crust. For the stations in the Luding source area, the average slow S-wave time delays are higher than those in the surrounding regions, indicating that stress accumulation level in the source zone was far more substantial than in peripheral areas during the seismogenic period of the 2022 Luding M_S6.8 event. This phenomenon reflects the differences in stress field changes and crustal response between the source area and the surrounding areas, further indicating that the stress concentration level in the source area is high, which may provide the driving force for seismic activity. The average time delay of the stations L5512 and L5513 located in the north of the source area is （4.219±0.469） ms·km⁻¹, the average post-seismic time delay of the stations CNXJ, AJW and NTW located in the central part of the source area is （6.118±1.878） ms·km⁻¹, and （4.812±1.880） ms·km⁻¹ for the stations BLG, XMC and SMI located in the south of the source area. And the slow S-wave time delay of stations in the north, south and central parts of the source area was low before the main shock, and then increased rapidly after the main shock. This indicates that the aftershock activity of the Luding M_S6.8 earthquake may continue, and the release and adjustment of the stress field may take some time. In addition, slow S-wave time delays at stations in aftershock-rich areas remain elevated above pre-seismic levels, implying that stress release and adjustment in these regions will persist for a period of time.