Abstract: Nanxiang basin is a Mesozoic-Cenozoic petroleum basin developed on the eastern Qinling fold orogenic belt in the late Yanshan movement and dominated by paleogene sediments. The analysis of geological structure and tectonic evolution plays a significant role in oil-gas exploration and structural research of basins above orogenic belts. Based on gravity, magnetism, electricity, seismic, drilling and logging data, guided by normal fault related fold theory and structural restoration theory, this paper systematically analyses the structural characteristics, stratigraphic distribution and tectonic evolution of Nanxiang basin, explores the controlling factors of geological structure differences in depressions, and analyses the origin of Nanxiang basin. It is considered that the Nanxiang basin is composed of several semi-graben depressions separated by deep and large faults and uplifts, with a tectonic framework of north-south zoning and east-west block and is divided into basement structural layer, upper Cretaceous structural layer, Paleogene structural layer and Neogene-Quaternary structural layer on the section. Its tectonic evolution can be divided into three extensional-convergent tectonic cycles:the Late Cretaceous fault depression-the Late Cretaceous inversion denudation, the Late Paleogene extensional rift-the Liaozhuang Formation inversion denudation and the Neogene depression period. The mudstone slippage and difference of the boundary faults caused by the difference of basement properties is the main controlling factors for the differentiation of geological structure in each depression of the basin. Nanxiang basin is a simple shear-type extensional detachment basin formed under the balance of mantle uplift and crustal subsidence under the NW-SE shear-tensile stress field since late Cretaceous.