In this study, seismic wave data of January 2009 to November 2015 are collected from China National Seismographic Network, and 16 156 Pg wave travel times from 1 820 seismic events (M_L=1.8~6.7 and epicentral distances less than 800 km) are selected to study the 3D Q-value distribution characteristics of P-wave in the southwestern Ordos margin. The results show that Q-values are relatively lower along the fault zones with "L" shape distribution in the southwestern Ordos margin, while on both sides of this zone, the Q-values are higher and vary greatly in their distribution. In the research area, the resistivity and velocity layers are significantly low in the Haiyuan and Tianshui—Lixian regions which have low Q-values, but the Weiyuan—Dingxi—Tongwei—Xiji region, which has higher Q-values, lacks a low resistivity layer. In addition, the Weihe Basin and Tianshui—Lixian region with a high heat flow have low Q-values, but surrounding areas have higher Q-values. There is a significant vertical deformation gradient belt and gravity change isoline along the Lintong—Chang’an—Fucheng—Pucheng fault. Moreover, the distribution of horizontal deformation along the fault is characterized by distinct stripped variations. The low Q-values in this area indicate that Q-value distribution is related to the vertical and horizontal deformations and gravity changes in the crust.