The Agro-Pastoral Ecotone of Northern China (APENC) serves as both a core area for grain and livestock production and a critical ecological barrier in northern China. Vegetation restoration has significantly changed the ecological environment and hydrometeorological conditions of the APENC; however, existing studies have not fully elucidated its impact processes and mechanisms. The results demonstrated significant upward trends in the Leaf Area Index (LAI) and Normalized Difference Vegetation Index (NDVI) across the APENC during 2000-2015, accompanied by an improved carbon sequestration capacity in terrestrial ecosystems and an overall increase in water use efficiency. Large-scale restoration projects have amplified evapotranspiration (ET) in most APENC regions, with enhanced ET-derived moisture contributing to 10.8% of precipitation through hydrological recycling processes. A pronounced increase in the Precipitation Recycling Ratio (PRR) was observed in APENC, indicating that vegetation restoration intensified the regional hydrological cycling to augment local precipitation. Synergistic effects between the East Asian summer monsoon and mid-latitude westerlies dominate evaporated moisture transport during the growing seasons. Vegetation restoration amplifies the regional vapor flux through enhanced transpiration, elevates the recycled moisture proportion in precipitation formation, and produces positive feedback on precipitation via intensified moisture recycling processes, making substantial contributions to precipitation in downwind regions. Vegetation restoration alters precipitation patterns through two synergistic mechanisms: \mathrm{①} albedo reduction enhances net radiation absorption, intensifies boundary layer turbulent energy, and promotes vertical moisture mixing; and \mathrm{②} Combined ET enhancement and horizontal vapor influx increase atmospheric humidity while lowering lifting condensation levels. These processes jointly modify the moist static energy and convective available potential energy, ultimately triggering deep convection development that alters the precipitation efficiency and reshapes the spatial distribution.