Air pollutant concentration is a function of emission rates and meteorology. To accurately evaluate the effect of control measures, the meteorological covariate must be corrected from the observations. This study quantified the impacts of emission abatement and meteorological condition on the interannual variations of SO2, NO2, CO, O3, PM10 and PM2.5 concentrations in 31 major Chinese cities using an optimized machine learning-based meteorological normalization technique. Overall, the annual average concentrations of SO2, NO2, CO, PM10 and PM2.5 were reduced by 86%, 51%, 99%, 86% and 88% from 2015 to 2020, respectively, in the studied cities, attributable to their emission reductions. However, the concentration of O3 was found with no significant decrease with the reduction of precursors. Emission abatement notably improved air quality between 2015 and 2018. Such a decline in emissions tended to progressively slow down since 2018. Overall, the meteorological conditions in 2016–2017 and 2018–2019 were unfavorable for a better air quality, while it became favorable in 2020–2021. Specifically, emission abatement in 2021 further lowered the concentrations of SO2, NO2, CO, and PM2.5, while the emission of PM10 increased. And changes in precursors emissions worsened O3 air quality. To meet the demand of improving air quality, more aggressive abatement measures need to be formulated to synergistically reduce NOx, volatile organic compounds, and coarse particles.