Abstract: The spatial and temporal variation of atmospheric tropospheric NO₂ column concentration in Kuitun City, Dushanzi District, and Wusu City (hereafter Kui-Du-Wu Region) was studied. The region is dominated by the petrochemical industry. Combined with topography, meteorology, industrial distribution and anthropogenic emissions, a ground-based multi-axis differential absorption spectrometer (MAX-DOAS) were used to invert the NO₂ column concentration at fixed points in the center of each city (09:00-20:00) and vehicle-mounted mobile monitoring (10:00-15:00) in the Kui-Du-Wu Region from February 2018 to July 2019. The results show that: (1) The daily variation of tropospheric NO₂ column concentration in Kui-Du-Wu Region is higher in the morning and evening than at noon, and is higher in winter than in summer. The detailed NO₂ column concentration is winter (11.8×10¹⁵ molec/cm²) > autumn (9.46×10¹⁵ molec/cm²) > spring (7.46×10¹⁵ molec/cm²) > summer (4.33×10¹⁵ molec/cm²). The highest values in the three sites all appear in winter (January), which is Dushanzi District (22.23×10¹⁵ molec/cm²) > Kuitun City (21.30×10¹⁵ molec/cm²) > Wusu City (18.34×10¹⁵ molec/cm²). (2) There is a spatial accumulation of NO₂ in the troposphere in Kui-Du-Wu Region, and there are significant differences within the region. The high values in different seasons mainly appear at regional traffic intersections (Kuitun overpass, Dushanzi overpass) and industrial concentration areas. The lowest values all occurred in Wusu City, the southwest of the Kui-Du-Wu Region, which is located in the upwind direction of the dominant westerly channel. (3) Combined with the analysis of the backward trajectory of the air mass, it is found that the movement of air mass in winter is not conducive to diffusion in both the horizontal and vertical directions in the Kui-Du-Wu Region. The northwesterly wind in summer leads to relatively high NO₂ concentration in the downwind section. The atmospheric NO₂ pollutants in this area are mainly transported locally, and there are transmission and accumulation of pollutants between cities. (4) The energy structure of Kui-Du-Wu Region is dominated by coal, and its stationary source emissions are dominated by factories and power sectors, while the atmosphere produced by the mobile sources of transportation in Wusu City. The total pollutant NO₂ emissions are much higher than Kuitun City and Dushanzi District, where coal is burned for 6 months in winter, and the low wind frequency (1.5-3.0 m/s) lasts for a long time. In addition, the 'valley wind' formed by the unique mountain basin structure has a deep temperature inversion layer, which is not conducive to the long-distance diffusion of pollutants. This research shows that the Kui-Du-Wu regional environment formed under the background of the energy industry structure is conducive to atmospheric pollutants. The pollution source is mainly local pollution.