Under the background of "dual-carbon" goals, regional, urban and industrial enterprises are formulating and implementing the "dual-carbon" goals action plan from the national level to the local level.Because of its objectivity and high temporal and spatial resolution, CO₂ simulation is deeply valued in the research of urban carbon emission.This paper took Beijing-Tianjin-Hebei region as the research area, used the high-precision CO₂ data observed by Picarro instrument from 2019 to 2020, used WRF model to simulate CO₂ transmission, analyzed the seasonal characteristics of CO₂ concentration change, evaluated the simulation effect of the model in the urban center, suburbs and background stations, and studied the factors that may affect CO₂ concentration, such as planetary boundary layer height and fossil fuel carbon emission.The three observation stations are the 325 m meteorological tower observation station at Institute of Atmospheric Physics, Chinese Academy of Sciences (Beijing station), Hebei Xianghe observation station (Xianghe station) and Shangdianzi regional background observation station (Shangdianzi station).The simulation results show that:The effect of Shangdianzi station is better than that of Xianghe station, and the effect of Xianghe station is better than that of Beijing station, especially in winter.The high value areas of CO₂ concentration are mainly distributed in urban areas, power plants and industrial areas, especially in Tangshan, Shijiazhuang and Handan areas.A large number of traffic and industrial emissions lead to a significant increase in CO₂ concentration, and the range of high value area is the largest in winter.In terms of daily and diurnal variations, there is an opposite trend between the planetary boundary layer height and CO₂ concentration.There is a positive correlation between fossil fuel carbon emissions (FFECO2) and total CO₂ concentration near the surface at the three stations.The correlations in winter and spring are higher than that in summer and autumn, and the proportion of FFECO2 is Beijing station, Xianghe station and Shangdianzi station from large to small.There are spatial differences and seasonal variations in the uncertainty of CO₂ transport simulation.