Abstract: As the core ore-controlling structure in the southern section of the Ailao Mountain gold mineralization belt，the Niukong-Huangcaoling Fault in Lyuchun County dominates the spatial distribution pattern of regional gold-polymetallic deposits. Through field observation，microscopic structure analysis and comprehensive mineralistic-geochemical research，the study systematically analyzed the structural ore-controlling mechanism of the fault zone. Research shows that the ore-controlling structure within the area presents a "three-level structural ore-controlling" model. The primary structure is composed of the northwest-oriented Niukong-Huangcaoling Fault and the Niugong-Datao Fault，which control the overall spatial distribution of the deposit in the study area. Under the drive of the northwest-southeast strike-slip stress field，secondary tensile faults develop in the enthroning area，providing a dominant migration chan⁃ nel and reservoir space for ore-forming fluids. The three-level conjugate joint system controls the shape of the ore body by adjusting the local stress field. The results of geochemical analysis show that the secondary structural fracture zone has gold mineralization anomalies，and the pyridine-silicification alteration has a strong correlation with gold mineralization anomalies，which can be used as a prospecting marker. By sys⁃ tematically determining the structural sequence and clarifying the 3D spatial configuration relationship of ore guiding，ore blending and ore storage structures，the accuracy of ore body positioning and prediction can be effectively improved.

Key words: ore-controlling characteristics, tectonic sequence, Niukong-Huangcaoling Fault