<p>Effective co-control of PM_2.5 and O₃ is complicated by the multifaceted influence of Aerosol-radiation interaction (ARI). Aerosol-meteorology interactions (ARI-met) alter the transport and dispersion of pollutants by modifying meteorological conditions, xwhereas aerosol-photolysis interactions (ARI-photo) influences the formation rates of pollutants by regulating photolysis rates. This study examines how ARI modulates compound pollution in the Beijing-Tianjin-Hebei region, with a focus on the distinct mechanisms of ARI-photo and ARI-met. WRF-Chem simulations revealed clear seasonal differences in their impacts: ARI-met increased PM_2.5 concentrations in summer and winter, whereas ARI-photo contributed to their reduction. In contrast, ARI-photo consistently suppressed O₃ levels across all seasons. Crucially, this study shows that the overall effect of ARI stems from the strong and often opposing interactions between these two mechanisms. These results provide a mechanistic explanation for the nonlinear response of air pollution to aerosol loading and highlight important implications for pollution control strategies. The results emphasize that effective air quality management requires accounting for the complex coupling between aerosol-photolysis and meteorological processes.</p> Graphical abstract <p></p>