China’s haze pollution presents the characteristics of high occurrence frequency, wide impact range and difficult treatment. Its causes and treatment path are the hot issues concerned by the government and scholars. The generation of haze will be affected by human social and economic activities. In recent years, China’s transportation infrastructure construction represented by high-speed railway construction has promoted the rapid improvement of inter city traffic accessibility. Some literature began to discuss the impact of high-speed railway construction and traffic accessibility improvement on economic development such as economic output and industrial structure, but limited to the availability of data, There is no literature to discuss the impact of high-speed rail and inter city traffic accessibility on haze pollution. The research brings traffic accessibility into the analytical framework of environmental economics. Firstly, the theoretical hypothesis of the impact of traffic accessibility on haze pollution is put forward from three aspects: factor allocation effect, industrial upgrading effect and industrial agglomeration effect. Based on the theoretical framework of Environmental Kuznets curve, a space econometric model constructed to calculate the shortest traffic time of road, ordinary railway and high-speed railway travel between cities as the quantitative method of traffic accessibility. Using the raster data of PM2.5 concentration in MODIS and MISR of 283 cities in Chinese mainland, we test the spatial correlation between urban traffic accessibility and Urban Haze pollution indicators, test the impact of traffic accessibility on haze pollution, and discuss the endogeneity and heterogeneity of the model. The mechanism of traffic accessibility on haze pollution is further analyzed. It is found that there is a significant spatial spillover effect of smog pollution between cities, and there is an inverted "U" relationship between economic development and smog pollution, which confirms the Environmental Kuznets curve; The empirical conclusion also proves that traffic accessibility can significantly reduce urban haze pollution, which is more significant in central and eastern cities; Taking the number of urban colleges and universities lagging behind for one period as the instrumental variable, it is found that the above conclusion is still robust; In the impact of traffic accessibility on haze, it may reduce or increase the heterogeneity of haze pollution in the short term, but in the long term, the improvement of traffic accessibility helps to reduce the traffic cost and friction between urban economies, promote economic growth and efficiency, and then reduce haze pollution; The impact of improved traffic accessibility on Urban Haze pollution is mainly reflected through factor allocation effect, industrial upgrading and agglomeration effect. Specifically, improved traffic accessibility will reduce urban haze pollution through factor allocation effect and increase urban haze pollution through industrial upgrading and agglomeration effect. The research shows that in the process of dealing with haze pollution, effective measures include: reducing the flow cost of factors, technologies, products and industries among cities by optimizing transportation infrastructure construction, and promoting the optimal allocation of resources and product market sharing; Aiming at the spatial correlation of haze pollution, an inter city linkage mechanism for haze prevention and control is constructed.