Abstract: Micangshan mountain located in the southern margin of Qinling orogenic belt was subject to squeezing action from north to south since the Indosinian, thus developing multiple sets of detachment structures that led to complex deformation features in the piedmont of Micangshan mountain. By means of field geologic sections, seismogeology profiles and balance recover, this paper analyzes the 2D structural characteristics of it, researches the spatial assemblage patterns of faults of 3D visualization in it. The result shows that the structures in the piedmont are of stratification: the deep structure was controlled by Sinian detachment zone, developing basement thrust fault; the middle structure was controlled by both Sinian and Triassic Jialingjiang detachment zones, and the shallow structure appeared a monocline controlled by the Jialingjiang detachment zone. The eastward gradual upraising of the top detachment zone of Jialingjiang formation resulted in decrease of shortening rate from west to east of the piedmont of Micangshan mountain. There exist five patterns of dual?structural fault combinations in the middle detachment zone: the secondary accommodate fault; a fault keeping parallel with other one and extending toward the two sides of it; a fault intersecting with other one; fault upraising gradually and subduction; generating new accommodate faults within original faults