## 1 Introduction  
With the continuous development of industrialization and urbanization, the air pollution issue has become increasingly prominent in the whole world. Large-scale and persistent haze weather frequently occurs, especially in countries that have not completed industrialization and with concentrated air pollutant emissions. Sustained haze weather is increasing, and yet economic growth depends on energy consumption, which will not change fundamentally for some time to come [1, 2]. The World Health Organization [3] used satellite measurement and atmospheric transport models to monitor data from more than 100 countries and more than 3000 urban and rural sites in the world. 92% of the world's population lives in areas with excessive PM2.5 levels. Currently, more than 50% of the world's population lives in cities, and it is expected that by 2030 the proportion of people living in cities will rise to two thirds [4]. As a huge gathering place for people and an important centre for people's work and life, cities have a direct impact on the development and health of the environment in terms of their economic [5], environmental [6], and social [7] aspects. In the process of rapid global economic growth, economic growth-oriented urban construction and development have led to increasingly serious urban pollution problems. The main manifestations are that the total amount of pollutant emissions far exceeds the environmental capacity, major air pollution accidents occur frequently, and point source pollution and non-point source pollution are intertwined. Industrial pollution and domestic pollution coexist and urban industrial structure adjustment, transformation and upgrading have become common problems that the urban economy needs to face when it develops to a certain stage [8]. The contradiction between air pollution and urban industrial structure adjustment and transformation has become the main factor restricting the stable growth and healthy development of the urban economy. More and more evidence shows that air pollution will directly or indirectly affect the urban industrial structure, for example, the industrial center of Essen, Germany has changed to become the green capital of Europe [9]; the development of emerging industries in Houston have promoted urban industrial transformation [10]. The impact of air pollution on the urban industrial structure has become a topic of general concern to national policymakers and a major issue that needs to be resolved. In many studies on industrial structure and air pollution, researchers have different perspectives and emphases, which can be roughly summarized into three types. The first view holds that there is a significant correlation between industrial structure and air pollution, and there is a positive correlation between the added value of secondary industry and air pollution, and a negative correlation between the added value of primary, secondary and tertiary industry and air pollution [9]. The second view is that there is no significant relationship between industrial structure and air pollution [10]. There is also the third view that there is an inverted \"U\" relationship between industrial structure and air pollution [11]. These three views differ from place to place and each view has its own characteristics. In addition, some scholars have conducted in-depth studies on the spatial distribution characteristics of industries and the impact of industrial structure adjustment on air pollution [12; 13]. For studies on the relationship between industrial structure and air pollution, the research methods mainly include logarithmic average Dirichlet index [14], time-varying parameter vector autoregression [15], gray correlation analysis [16], input-output model [17], and geographic information spatial analysis technology [18].