Abstract: Collecting the seismic data from 2009 to 2016 recorded by Henan Xiaolangdi Reservoir Digital Seismic Network, and combining with the results obtained by Double-Difference Hypocenter Locations, this study has obtained the S wave splitting parameters of 8 digital seismic stations distributed in the Xiaolangdi Reservoir region using the SAM method. The results show that the earthquakes occurred in the Xiaolangdi reservoir area are mainly distributed near the Shijing River fault, which is located in the middle of the reservoir area. The dominant polarization direction of the fast shear wave is 100.4°±45.0° and the average time delay of the slow shear wave is （2.87±1.13）ms/km. The dominant polarization direction is consistent with the direction of the regional principal compressive stress of the South China Block. The dominant polarization direction of the fast shear wave of most stations in the region is consistent with the fault strike of the region. The slow wave time delay is equivalent to the results obtained from the North China Block.