In this paper, based on the hour-by-hour mass concentration of O3 in Hefei from 2018 to 2021, the backward trajectory analysis, the potential source contribution Function (PSCF) and concentration weighted trajectory (CWT) methods were used to cluster the backward trajectories during O3 pollution, as well as to analyze the O3 potential sources simultaneously. The results show that Hefei is dominated by short-range transport airflow, primarily from the east, and that the areas with high WPSCF values are the eastern part of Hubei province (Wuhan), the northern cities of Hefei, the eastern part of Tangshan, and the coastal area of the northern part of Shandong province. The results of the CWT and PSCF assessments are generally consistent. However, the CWT data demonstrate that emissions from Hefei and nearby cities have an impact on O3 accumulation. To prevent and control O3 pollution, it is necessary to strictly control the discharge of local pollution sources and strengthen the joint prevention and control of surrounding areas.