Abstract: In order to clarify the pore structure characteristics of the deep gas reservoir sandstone and its influence on the exploration and development of the deep tight sandstone gas, the core observation, casting sheet, gas measuring properties data were used to analyse the characteristics of the deep tight gas reservoir sandstone, then based on the fractal theory combined with the high pressure mercury experimental data to characterize its microscopic pore structure characteristics, and discuss the pore fractal characteristics of deep tight gas reservoir and its influence on tight gas transport and enrichment in the study area. The results show that: ① deep tight gas storage sandstone of He8 layer in Qingshimao area is mainly thick medium-coarse clastic quartz sandstone and quartz sandstone, gas storage pores are mainly intercrystalline, debris dissolution, residual intergranular and intergranular pores. ② The four types fractal characteristics of pore structures in the study area are obvious, and the heterogeneity of the overall pore is weakened with the smaller pore size. The type III and IV do not develop large pores, type I and II pores not only develop large pores, but also have less complex pores and small holes, and type I and II pores in relatively high pores and high permeability zones are the dessert types for exploration and development. ③ Large, medium and small pores with weak heterogeneity are the main occurrence space of tight sandstone gas, the large pore with strong heterogeneity is the advantage channel of movable tight gas microscopic migration, and the medium and small pores with strong heterogeneity is the main shielding condition for tight sandstone gas to retain weak inhomogeneous pores and accumulate. Therefore the exploitation of He8 tight sandstone gas in the Qingshimao area should pay attention to the gas sand storage body with type I pore structure and medium-high pore, which develop weakly heterogeneous large pore and highly heterogeneous medium-small pore.