The characterization and geological modeling are of great significance to exploration and development of fractured tight sandstone gas reservoir. Taking the Dabei-12 gas reservoir in Kuqa Depression of Tarim Basin as an example, the types and occurrence, influence factors and formation sequence of structural fractures were characterized based on core, rock thin section, imaging logging and other data. Then, the small scale and large scale fracture model of the Dabei-12 gas reservoir were established by stochastic and deterministic fracture modeling method respectively, and a total fracture model was established by superimposition of the two models. The results show that: (1) The Dabei-12 gas reservoir, an anticlinal gas reservoir which formed under the background of NS tectonic compression due to the Yanshanian movement and Himalayan movement, is located in the Bozi-Dabei area of Kelasu structural belt, Kuqa Depression. The target layer of the Dabei-12 gas reservoir is the tight sandstone of Lower Cretaceous Bashijiqike Formation. The macroscopic fractures in the Dabei-12 gas reservoir are mainly vertical or with high dip angle, and shearing and tensile fractures are both developed to some extent. The microscopic fractures can also connect matrix pores and therefore enhance the connectivity of reservoir. (2) Under the geological background of Dabei-12 gas reservoir, the development extent of structural fractures is related to average thickness of single layer in condition of same lithology, and distance to fault and lithology in condition of same or similar thickness of single layer. Taking fine sandstone in the Dabei-12 gas reservoir as an example, the density of structural fractures in fine sandstone decreases with the increase of thickness of single layer, and so does the decreasing amplitude. In condition of similar thickness of single layer, the density of structural fractures shows good negative correlation with the distance to faults. As to different lithology in the same condition, the fine sandstone has the highest density of structural fractures, the coarse sandstone and medium sandstone take the second place, while siltstone and finer lithology have low density. (3) There are 3 periods of structural fractures in the Dabei-12 gas reservoir, which are the Late Yanshanian period (Late Cretaceous-Paleogene), the Middle Himalayan period (Neogene Kangcun period), and the Late Himalayan period (Neogene Kuqa period-Quaternary) respectively. The second and third period fractures formed at the Middle and Late Himalayan periods are the critical factor of efficient accumulation of natural gas. (4) The hinge of an anticlinal reservoir has structural fractures with low density but high aperture and permeability, and therefore has always high production. The wings of a faulted-anticlinal reservoir have structural fractures with high density but low aperture and permeability, and fracturing measures should be taken to improve production. This study can provide data foundation for the establishment of fracture property equivalent model and gas reservoir numerical simulation, and then serve for the development of gas reservoir.