As the global climate change problem is becoming more and more serious , China has made the commitment to the "dual-carbon" target. At present , our country has not fundamentally solved the issue of PM2.5 pollution. Meanwhile , O3 pollution is gradually worsening, and incidents of combined PM2.5 and O3 occur frequently. Therefore, the sustained improvement of PM2.5 and O3 pollution is of great significance to protect people's health and achieve carbon neutrality goals. To better understand and address PM2.5 pollution, this paper provides an overview of the effects of NOx and NH3, emissions, as well as secondary organic aerosols on PM2.5 pollution. Additionally, it summarizes current research on the influence of emission sources (nitrogen oxides, volatile organic compounds) and meteorologica factors (temperature, relative humidity, UV radiation intensity, wind speed, boundary layer height etc.) on O3 pollution in China, which provides methodological and theoretical support for improving O3 pollution and developing reduction strategies in our country. Furthermore , this paper summarizes the research progress on the regional delineation , chemical mechanism and influencing factors of PM2.5 and O3 combined poluton in China . aiming to provide relevant references and guidance for China's follow-up action plan to improve air quality, protect the environment, and realize the synergistic management of PM2.5 and O3 combined pollution under the "dual-carbon" policy.