Zhangjiakou-Chengde area (ZC area) is a strategic place for the environmental optimization of Jing-Jin-Ji Urban Agglomeration. The quantitative assessment of water conservation and soil conservation is of great significance to maintain the ecosystem safety. The Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model, spatial partial correlation statistical mapping, and scenario simulation are used to comprehensively analyze the temporal and spatial change characteristics and complex relationships of water conservation and soil conservation services in ZC area in recent 20 years, and quantitatively evaluate their response to climate and land use change. The results showed that water conservation and soil conservation intensity in ZC area increased at the rate of 0.97 mm/a and decreased at the rate of -0.50 t hm^-2 a^-1 from 2000 to 2019, respectively, which were spatially low in the west (Bashang plateau) and high in the east (Yanshan Mountain). The water conservation and soil conservation were strong and mainly synergistic in the northern Hebei and Yanshan Mountains deciduous broad-leaved forest ecological zone; while the trade-off relationship was more dominant in the Bashang plateau grassland and agroecological zone. The spatial relationship between water conservation and soil conservation is complex, which is closely related to regional land use type, vegetation coverage and slope. The scenario simulation results showed that the impact of precipitation (r=0.90, P<0.01) on water conservation service was much greater than the potential evapotranspiration (r=-0.37, P>0.1), and the greater variation of precipitation, the stronger water conservation. There was a linear positive correlation between precipitation and soil conservation service, and each 10% increase (decrease) of precipitation caused the increase (decrease) of 74.7 t/hm² in soil conservation intensity. It is expected that water conservation capacity of ZC area will be significantly improved in 2030, while soil conservation capacity will not change much. By then, human activities (such as the policy measures related to ecological protection or planning control) will become the significant impact on improving water conservation service. In order to improve water conservation and soil conservation services in ZC area, the comprehensive impact of various factors should be considered to formulate more reasonable ecological protection policies. It is suggested to continue to strengthen the construction of national key ecological projects, to limit the expansion of construction land as much as possible and improve vegetation coverage to protect the natural ecosystem, especially to strengthen the protection of key slope zones, which should be the focus of water conservation and soil conservation services in the future.