Environmental stress is used to indicate the integrated pressure on regional environmental system caused by various pollutant outputs during human life and production activities. Based on the pollutant emission and socio-economic database of the counties in Beijing-Tianjin-Hebei (BTH) region, this paper comprehensively calculates the environmental stress index (ESI) by entropy weight method at the county scale, and analyzes the spatio-temporal pattern and the differences among four types of Major Functional Zones (MFZ) in this region from 2012 to 2016. In addition, the socio-economic driving forces of environmental stress is quantitatively estimated by means of geographical weighted regression (GWR) method based on the STIRPAT model framework. The results show that: (1) The situation of environmental stress in the BTH region had been significantly alleviated, with an ESI decline of 54.68% since 2012. The decline was most significant in central urban areas of Beijing, Tangshan, Tianjin and Shijiazhuang, and Binhai New District. The degree of environmental stress in counties decreased gradually from the central urban areas to the suburban areas, and the high-level stress counties were eliminated in 2016. (2) The spatial spillover effect of environmental stress had been further enhanced on the county scale since 2012, and the spatial locking and path dependence emerged in cities of Tangshan and Tianjin. (3) Urbanized zones (development-optimized and development-prioritized zones) are the major bearing areas of environmental pollutants in the BTH region, with ESI accounting for 65.98% of the whole region, which should be focused on prevention and control of environmental pollution. (4) The controlling factors of environmental stress in counties include population size and economic development level. In addition, technical capacity of environmental disposal, agricultural production input intensity, territorial development intensity and urbanization had a certain degree of influence. (5) There was spatial heterogeneity in the driving effects of various driving factors on the environmental stress. Therefore, it is necessary to adopt differentiated environmental governance and reduction countermeasures from emission sources, according to the intensity and spatial difference of driving forces, so as to improve the accuracy and adaptability of environmental collaborative control in the BTH region.