Inter-city adjacent areas constitute important spaces for overcoming administrative barriers and facilitating coordinated regional development through factor mobility. Population and industry are two core variables shaping regional development, and understanding how industrial structures shape population mobility is therefore essential for promoting coordinated regional development. Using mobile signaling and industrial data, this study examines population mobility patterns in the inter-city adjacent areas of Beijing and investigates how industrial characteristics influence these patterns. The results show that: ① Population mobility exhibits a pronounced concentric spatial structure, and short-distance cross-boundary mobility has become the dominant form of daily interaction. Mobility is unevenly distributed, with populations from areas outside Beijing primarily flowing into the city. ② On weekdays, distinct cross-boundary commuting corridors are evident, particularly in the Beijing–Tianjin–Langfang and Beijing–Baoding areas, while non-commuting mobility is concentrated mainly within Beijing and the Beijing–Tianjin–Langfang area. On weekends, commuting mobility declines significantly and becomes concentrated in the Beijing–Langfang area, whereas non-commuting mobility increases markedly in both intensity and spatial extent. ③ High-value-added, innovation-oriented industries tend to attract cross-boundary commuting populations. Districts within Beijing, owing to their stronger innovation capacity, draw substantial numbers of commuters from surrounding areas. Finance and commercial services and technology, as well as R&D services, are associated with inflows of commuting populations, whereas daily life and consumer services tend to attract non-commuting populations. Diversified industrial agglomeration significantly promotes both commuting and non-commuting mobility, whereas specialized agglomeration based on traditional industries tends to inhibit population mobility.