Abstract: Provinces in China have made remarkable development in introducing the ecological compensation for air pollution. However, the cross-regional ecological compensation for air pollution develops slowly, which is not conducive to the in-depth promotion of air pollution control. Taking the Beijing-Tianjin-Hebei (BTH) region, a typical area of air pollution, as an example, this study proposes a compensation mode that combines inter-provincial transfer payments with intra-provincial funds allocation based on the regional collaborative emission reduction optimization model. The compensation standards under a cost-minimization scenario for both inter-provincial and intra-provincial cities are calculated. The results show that the BTH region could save emission reduction costs through regional collaborative emission reduction. Taking the emission reduction of SO₂ and NO_x in the BTH region from 2015 to 2020 as an example, the emission reduction cost saved through collaborative emission reduction accounted for approximately 0.07% of the total GDP of the BTH region. Under the optimal emission reduction plan, Hebei province undertook a part of the emission reduction task for Beijing and Tianjin. In order to promote regional equity, economic compensation from Beijing and Tianjin was vital to alleviate the cost burden on Hebei province. Among the cities in Hebei province, Tangshan and Handan received the most compensation funds. The results provide a quantitative reference and policy enlightenment for the construction of horizontal ecological compensation mechanism for air pollution.