As an important parameter for site classification, the average shear wave velocity at a depth of 30 m ( v _S30 is widely used in domestic and international seismic design codes for buildings and structures, as well as in the correction of local site effects. However, the applicability of the v _S30 data commonly used in China, which are provided by the United States Geological Survey (USGS), requires further verification. Based on the correlation between terrain slope in Sichuan Province and shallow average wave velocity, as well as the relationship between v _S30 and shallow average shear wave velocity, this paper proposes a v _S30 dataset for Sichuan Province paper. The dataset is then applied to the seismic intensity assessment of the Wenchuan M_S8.0 earthquake. The results show that compared with the widely used v _S30 data provided by USGS, the v _S30 results for Sichuan Province obtained from this study are closer to the actual situation. The rapid seismic intensity assessment of the Wenchuan M_S8.0 earthquake using the v _S30 data in this study provides more accurate judgments of heavy and severe disaster areas. The results can improve the accuracy of seismic emergency outputs in Sichuan Province in the future, offering valuable first-hand reference materials for post-earthquake emergency command and rescue operations.