<p>Scientific identification of the spatial heterogeneity and influencing factors of PM_2.5 population exposure risk in the Beijing-Tianjin-Hebei region is essential for regional atmospheric linkage management. Using PM_2.5 concentration and population distribution data from 2000 to 2022, this study applied Kriging interpolation, Theil-Sen Median trend analysis, and the Mann-Kendall test to analyze the spatio-temporal evolution of PM_2.5 concentration in the Beijing-Tianjin-Hebei region. A population risk exposure model was developed to analyze the spatial and temporal pattern of population exposure risk, and the factors influencing population exposure risk were analyzed by using Geo-detectors. The results show that: (1) the PM_2.5 concentrations show a fluctuating upward and then downward trend from 2000 to 2022, and the PM_2.5 concentrations in the northwestern part of the Beijing-Tianjin-Hebei region are significantly lower than those in the southeastern part; (2) the spatial and temporal pattern of the PM_2.5 population exposure risk shows a trend of mitigation from the southeast to the northwest, and the higher risk indexes are found in Handan, Xingtai, Langfang, Shijiazhuang, and Tianjin; (3) green infrastructure and secondary industry value-added were primary factors, while factors such as automobile ownership and industrial dust also play a role in driving the risk. It is of great significance to explore the spatial and temporal patterns of PM_2.5 exposure in the Beijing-Tianjin-Hebei region to improve people’s health and well-being.</p>