Abstract: Based on the pollutants and meteorological factors observed data of 17 cities in Henan province from 2015 to 2021, the spatiotemporal distribution characteristics of PM_2.5-O₃ co-pollution and the relationship with meteorological conditions in Henan province were analyzed. The results revealed that the PM_2.5-O₃ co-pollution in Henan province accumulated for 8~60 d from 2015 to 2021, with more occurrences in Pingdingshan, Jiaozuo, Zhengzhou, Xinxiang and Anyang, and fewer occurrences in Zhoukou, Sanmenxia, Xinyang, Hebi and Nanyang. The PM_2.5-O₃ co-pollution mainly occurred from April to October. O₃ was positively correlated with PM_2.5 in summer and negatively correlated in winter. A weak correlation in spring and fall was found. When the PM_2.5 pollution level was excellent, PM_2.5 was positively correlated with O₃, and other PM_2.5 pollution levels were negatively correlated. The main temperature intervals at the time of PM_2.5-O₃ co-pollution in Henan province were 20.1~25.8 ℃, the relative humidity (RH) intervals were 54.0%~69.0%, the wind speed intervals were 1.3~2.5 m/s, and the wind directions were NE—E and SSE—SSW. Pollution transmission in the southern surrounding cities of Zhengzhou has made an important contribution to its PM_2.5-O₃ co-pollution.