Abstract: In order to evaluate the environmental air quality of wenshan,the average daily concentration of the ambient air quality routine monitoring index in 2020 was selected to analyze the spatio-temporal distribution characteristics of pollutants.The results showed that the ambient air quality in Wenshan Prefecture was generally good in 2020,but the weather pollution hazards still existed in some counties and cities in some periods.The main pollutants affecting the ambient air quality in Wenshan were PM_2.5,O₃ and PM₁₀.The pollution season mainly occurred in March to May and November.The concentration in Yanshan County and Maguan County increased slightly,while the concentration in other counties decreased.The air quality in Guangnan County was relatively poor,and the air quality in Xichou County was relatively good.The correlation between O₃ and PM_2.5 concentration change and humidity was most obvious.Local and Southeast Asian biomass combustion had a certain contribution to air pollution in Wenshan,which has caused the compound and regional pollution features mainly PM_2.5 and O₃.