Abstract: Based on the meteorological data of Chengde Meteorological Station and the O₃ data of Chengde Environmental Monitoring Station, the meteorological conditions of O₃ heavy pollution process from May 22 to June 1, 2015 were analyzed. It was found that from May 22 to June 1, O₃ pollution presented a trend of first increase and then decrease, and O₃ pollution was the most serious on May 25, and that the daily distribution of O₃ concentration was unimodal, with high concentration in the afternoon and low concentration in the morning. The weather situation during the O₃ pollution in Chengde City was as follows:500 hPa was controlled by high pressure ridges; 850 hPa had more than 20℃ warm center with a strong warm advection flowing to Chengde City, the southerly airstream prevailed because the sea level pressure field was affected by the mean pressure field at the front of the low pressure and at the rear of the high pressure. The meteorological conditions contributed to O₃ pollution include high temperature, high wind speed, strong radiation, long sunshine hours, low atmospheric pressure, low relative humidity, but less-affected visibility. The meteorological conditions for the O₃ pollution process are favorable, and the effect of the meteorological conditions on O₃ pollution is mainly to promote the generation and regional transmission of O₃ pollutants. In this process, the middle and northern part of Beijing, Tianjin and Hebei Province suffered severe O₃ pollution. With the help of south wind and southwest wind, the O₃ pollution was transported to Chengde from Tangshan and Beijing City.