Abstract: Based on the ozone monitoring data and meteorological data from 2014 to 2019 in Kunming, the characteristics of ozone pollution and the influence of meteorological conditions on ozone pollution were analyzed; meanwhile, the weather situation, and the horizontal and vertical external transports of ozone pollutants were generalized and summed up in Kunming. The results showed that: Firstly, O₃ concentration was increasing year by year, and pollution mainly occurred in spring and summer. Ozone was significantly positively correlated with temperature and wind speed, and negatively correlated with relative humidity. Secondly, the ozone pollution events of Kunming were classified into five synoptic types, among which the most frequent were low trough eastward-moving type, two-high-convergence type and easterly wave type. The effect of weather systems was conducive to the horizontal transportation of high concentration O₃ from upstream regions to Kunming. Hybrid Single Particle Lagrangian Integrated Trajectory(HYSPLIT) backward trajectory further verified that the air mass movement path was consistent with the pollutant concentration and weather system. Lastly, in the vertical direction, 1−2 days before the pollution process occurred, the high concentration O₃ air in the lower stratosphere was transported vertically to the troposphere and the near ground. Therefore, favorable meteorological conditions, combined with the horizontal and vertical external transports of O₃, were conducive to the accumulation and generation of pollutants, hence resulting in O₃ exceeding the standard in Kunming.