Abstract: In order to explore the pollution characteristics of particulate matter and O₃ in Yunfu City, the concentrations of six ambient air pollutants and meteorological factors in Yunfu City from 2018 to 2020 were analyzed using multivariate statistical analysis methods, and the pollution process of PM_2.5 and O₃ in winter from December 25^th to 29^th, 2020 was studied. The results showed that: (1) The monthly average concentrations of PM_2.5, PM₁₀, NO₂, CO showed the characteristics of low in summer and high in winter. The 90% pentitle of maximum daily 8-hour average ozone showed the characteristics of high in summer and autumn, and low in spring and winter. (2) The hourly concentrations of PM₁₀, PM_2.5, CO exhibited wave-shaped changes. The hourly concentrations of PM_2.5 and CO all reached their maximum at 09:00, and the maximum hourly concentration of PM₁₀ appeared at 02:00. The hourly concentrations of O₃ and SO₂ showed a single-peak type changes. The maximum hourly concentration of O₃, SO₂ appeared at 16:00 and 10:00, respectively. The hourly concentration of NO₂ showed a single-valley type change, in which the minimum appeared at 14:00. (3) The concentrations of PM_2.5-10, SO₂, NO₂ and O₃ are all positively correlated with the concentration of PM_2.5. PM_2.5-10, SO₂, NO₂ and O₃ had certain homology with the concentration of PM_2.5. The concentration of O₃ was negatively correlated with the concentrations of NO₂, CO, and the concentration of O₃ was more closely related to the concentration of NO₂. The temperature was positively correlated with the concentration of O₃, and negatively correlated with the concentrations of SO₂, NO₂, CO, PM₁₀, PM_2.5, and the temperature had a stronger correlation with the concentrations of NO₂, CO, PM₁₀, PM_2.5, O₃ in summer and autumn. Air pressure was positively correlated with the concentrations of NO₂, CO, PM₁₀, PM_2.5, and the correlation is stronger in summer and autumn. Humidity was negatively correlated with the concentrations of SO_2, PM₁₀, PM_2.5, and O₃, and had the strongest correlation with the concentration of O₃. (4) From December 25^th to 29^th, 2020, the PM_2.5 pollution in the urban area of Yunfu City was affected by static and stable weather, the O₃ pollution was related to the high-temperature solar radiation in the afternoon on the 28^th and the external input from the O₃ polluted air mass in the Pearl River Delta. Using ART-2a to analyze the composition of the particles collected during the period, eight single particles of K, EC, OC, ECOC, HM, LEV, Na, and SiO₃ were obtained. There were obvious sulfate and nitrate peaks in the EC, OC, and ECOC spectra throughout the entire period. The hourly concentration of PM_2.5 was significantly positively correlated with the numbers of sulfate ion, nitrate ion, silicate ion, ammonium ion, and chloride ion, which indicated that the secondary reaction and aging process had a significant impact on the PM_2.5 pollution. The coordinated prevention and control of PM_2.5 and O₃ pollution in Yunfu City needs to focus on the characteristics of local pollutants and the impact of emission sources, as well as the impact of external polluted air masses, especially the impact of polluted air mass from the Pearl River Delta region.