Abstract: As a key area of air pollution prevention and control in China, the concentration of particulate matter (PM_2.5) in Beijing-Tianjin-Hebei (denoted as BTH) region is decreasing year by year, while the concentration of ozone (O₃) is increasing. Therefore, the coordinated control of PM_2.5 and O₃ is very critical and urgent for the continuous improvement of air quality in BTH region. Constructed the city-level computable general equilibrium model (CGE) of BTH region and simulated the marginal abatement cost curve of Nitrogen Oxides (NOx) and Volatile Organic Compounds (VOCs), which are the common precursors of PM_2.5 and O₃. On this basis, the evaluation model of PM_2.5 and O₃ co-control in BTH region is constructed, which can determine the NOx and VOCs co-emission reduction schemes with the least cost under different air quality targets. The results are as following. The total emissions of NOx and VOCs in BTH region will reduce by 47.6% and 42.8% compared to 2017, which can not only make the concentrations of PM_2.5 and O₃ meet the national secondary standards but also cost 992.81 billion yuan that is the lowest. In general, PM_2.5 and O₃ co-control evaluation model is built based on the BTH urban policy simulation platform, which can provide technical support for the formulation of PM_2.5 and O₃ co-control scheme in BTH region.