With its high energy consumption and pollutant emissions, the iron and steel industry is a significant source of air pollution and carbon emissions in the Beijing-Tianjin-Hebei (BTH) region. To improve air quality and reduce greenhouse gas emissions, a series of policies involving ultra-low emission, synergistic reduction of pollution, and carbon application have been implemented in the region. Based on a co-control effects coordinate system, marginal abatement cost curve, and numerical modeling, this study assesses air pollutant and CO2 emission characteristics in the iron and steel industry of the region, along with the synergistic benefits of typical technologies. The results showed that: (1) Due to the large number of iron and steel enterprises and production in Tangshan and Handan, emissions in those two places were high. The sintering process is the main source of SO2, NOx, PM2.5, and CO, accounting for 64.86%, 55.15%, 29.98%, and 46.43% of the total emissions, respectively. (2) Among the typical measures, industrial restructuring and adjustment of the energy-resource structure had the highest emission reduction effect. High emission reduction potential and low-cost technologies such as TRT need to be promoted. (3) In the highest steel production city, Tangshan, the contribution of iron and steel to PM2.5, SO2, and NO2 was 30.51%, 50.67%, and 42.54% during the non-heating period. During the heating period, pollutants emitted from the combustion of fossil energy for heating increased, while iron and steel emissions decreased to 23.7%, 34.32%, and 29.13%. By 2030, after implementing ultra-low emission policies and typical synergistic reduction technologies, the contribution of the iron and steel industry to air quality significantly decreased.