<p>Radial anisotropy structures are essential for understanding tectonic stress fields and distinguishing between lowvelocity zones (LVZs) associated with sedimentary basins and fault damage zones, offering critical insights for comprehensive seismic hazard assessments. This study employed ambient noise tomography to investigate the fault zone and surrounding structures of the Chenghai Fault in the Binchuan Basin, Yunnan Province, China. Utilizing three-component waveform data collected from a linear dense seismic array consisting of 114 stations, we constructed a high-resolution shear wave velocity and radial anisotropy model. Our results reveal notable variations in radial anisotropy across the study region, with pronounced negative radial anisotropy surrounding the Chenghai Fault, likely reflecting fault damage. In contrast, positive radial anisotropy is observed beneath the Dongshan Mountain, indicative of extensional stress. The LVZ beneath the Binchuan Basin exhibits positive radial anisotropy, suggesting that this LVZ is primarily due to sedimentary deposits. Based on the shear wave velocity and radial anisotropy structure, we infer that the Chenghai Fault, influenced by east-west extensional tectonics, behaves as a high-angle normal fault. Additionally, another fault with a relatively lower dip angle is identified within the Binchuan Basin. The tectonic activity of the Chenghai Fault played a significant role in the initiation of sedimentation within the Binchuan Basin during the Neogene period. These findings are crucial for advancing the understanding of fault dynamics and provide essential insights for refining seismic hazard assessments in the region.</p>