Ecosystem services (ESs) are essential for human society, and maintaining harmony between ecosystems and humanity to mitigate ES degradation is the fundamental basis for achieving a sustainable state. However, due to the influence of land use and land cover (LULC) and other ecological-economic factors, the quality and capacity of ESs supporting human welfare continue to decline, and the specific processes involved in this decline are still unclear. In this paper, a dynamically reconstructed assessment model was designed based on the equivalent factor method to estimate the Ecosystem service value (ESV) and to reveal its spatiotemporal response to LULC in a hilly area located in the Economic Circle of Beijing-Tianjin-Hebei during the period from 2000 to 2020; the structural equation model was also used to detect the detailed contribution of ecological-economic factors on ESV. Results showed that due to the decrease in forest land and the sprawl of orchard and construction land between 2000 and 2020, the spatial richness of various ecosystem services reduced, resulting in a decline in the total value of regional ecosystem services. The interaction of LULC, ecological and economic factors increased the regional heterogeneity of ESV. LULC caused a significantly direct impact on ESV (0.543), while economic factors had a negative direct impact on ESV (−0.26). Moreover, terrain factors affected the ESV through LULC and meteorological factors (0.259). The results of this study enrich our understanding of the detailed spatiotemporal variation and driving factors underlying the diminishing ESV in a rapidly developing hilly area, which has substantial guiding implications for land planning and ecosystem protection policies. © 2022 by the authors.