Abstract: This paper briefly analyzes the genetic, kinematic and dynamic features of a large multi-level sheeted thrust-nappe structure in the South Panjiang River and North Panjiang River valleys. The authors consider that the "megafacies change line" of the Triassic in southwestern Guizhou determined by predecessors is actually an exposure line of the front of a giant arcuate nappe structure. This nappe structure, which originated in the Late Mesozoic, is superimposed on the pre-existing N-S-and E-W-trending tectonic belts. This reflects shallow-level detachment within the plate and is a manifestation of strain softening and localization. The discovery and study of this giant nappe structure are of theoretical and practical significance for understading the crustal structure and deformation features in southwestern Guizhou and guiding the work of geological mapping in sedimentary areas and prospcting and exploration for Carlin-type gold deposits in the "Gold Triangle" area.