Based on the micro data of 45 380 cases of respiratory diseases in a hospital from January 2013 to December 2018, this paper uses the Poisson regression model to analyze the statistical relationship between urban air quality and the incidence of various respiratory diseases. The confirmed amount of various respiratory diseases in the hospital was used as the proxy variable of the incidence of respiratory diseases and matched with the monthly average concentration index of various air pollution of Chongqing from the monthly report of urban air quality issued by the Ministry of Ecology and Environment of the People’s Republic of China. The results show that air pollution is an important inducement of respiratory diseases. When the monthly average concentration of PM_2.5 increases by 1 μg/m³, the number of cases of bronchial asthma, chronic bronchitis, upper respiratory tract infection, community-acquired pneumonia, emphysema and chronic obstructive pulmonary diseases will increase by 0.2% to 1.1%.