In this paper,we applied the v_p/v_s model consistency-constrained double-difference seismic tomography method with the earthquake catalogue and phase report constructed by machine learning and t,to obtain the seismic location and 3D v_p,v_s,v_p/v_s structures in the reservoir areas of western Guizhou Province. The results show that the velocity structures in the study area are of obvious heterogeneity,and different tectonic deformation zones show different velocity structure characteristics. At the depth of less than 10km,the NW-trending Weining tectonic deformation zone that crosses the central part of western Guizhou Province shows significant low-velocity anomaly bands,revealing the depth and range of the influence of the Weining-Shuicheng fault zone. Due to the influence of lithology and fluid permeability,the velocity structures at 0km depth in the reservoir area generally show the characteristics of low-velocity and high v_p/v_s, including Jiayan,Pingzhai,Guangzhao and Mamaya reservoir areas. The spatial distribution of relocated earthquakes provides the evidence of the geometric distribution characteristics of a large number of buried faults. Combined with the 3D velocity structure,it is inferred that the seismic activity in this area is related to the fault activation around the reservoir.