Abstract: In recent years,ozone pollution has become one of the main pollutants of air pollution in many cities of China.In this paper,hourly air quality monitoring data from 5 representative monitoring sites in Haikou City in 2020 and the corresponding site meteorological element monitoring data were used for research and analysis.The results showed that the numbers above third-level days were 11 days in Haikou City in 2020,and the primary pollutant was ozone.The period of high ozone concentration mainly occurred from October to December.The maximum of O₃-8 h occurs time period mainly occurred at 14:00-17:00,and the lowest value occurred at 05:00-08:00.Correlation analysis between the daily mean value of meteorological elements and O₃-8 h was highest temperature>average temperature>relative humidity>precipitation>sunshine hours>wind speed.The downdraft and northeast airflow around the typhoon were one of the main factors that caused the ozone concentration in Haikou to exceed the standard.The sinking airflow was more conducive to the accumulation of ozone concentration in the lower atmosphere.Under the action of the northeast airflow,the transmission of pollutants from the northeast to the region was also one of the main factors leading to the increase in ozone concentration in Haikou.