Abstract: In recent years, O₃ pollution has occurred frequently in various regions of China, which has become an important factor restricting the further increase of the proportion of excellent days. It is of great significance to analyze the causes and influencing factors of O₃ pollution for scientific prevention and control of O₃ pollution. On the basis of sorting out and analyzing a large number of related studies, this paper further divides the formation mechanism of O₃ pollution in troposphere into three parts: main causes, key driving factors and important influencing factors. Among them, the precursors with high emissions and high reactivity are the main causes of O₃ pollution, meteorological factors and climate characteristics are the key driving factors of O₃ pollution, and three-dimensional transmission (i.e. stratospheric input, vertical mixing and horizontal transportation) is the important influencing factors of O₃ pollution. At present, the research on the causes and influencing factors of O₃ pollution in troposphere is basically clear at home and abroad, but the related research needs to be strengthened in the aspects of exploring the potential influencing factors of O₃, establishing the comprehensive meteorological characteristic index of O₃ pollution and comprehensive analysis of the causes and sources of O₃ pollution.