Abstract: Digital rural construction serves as a crucial policy instrument for advancing rural revitalization, facilitating integrated urban-rural development, and achieving the dual carbon goals. It plays a pivotal role in promoting the green transformation and low-carbon development of agriculture. Based on balanced panel data from Chinese counties spanning 2007 to 2024, this paper constructs a staggered difference-in-differences model to empirically examine the impact of digital rural construction on county-level agricultural carbon emissions and its underlying mechanisms. The results indicate that: first, digital rural construction significantly reduces county-level agricultural carbon emissions, and this conclusion remains robust after a series of reliability and endogeneity tests; second, mechanism analysis reveals that digital rural construction exerts an emission reduction effect by fostering new forms of rural agriculture; third, extended analysis demonstrates that the emission reduction effect tends to break through municipal boundaries while remaining constrained by provincial boundaries, alongside a positive effect on ensuring grain production; fourth, heterogeneity analysis shows that this impact is more pronounced in major grain-producing areas, regions with lower levels of agricultural mechanization, and counties with weaker endowments of arable land resources. Based on these findings, it is essential to further harness the emission reduction potential of digital rural construction and promote the green and low-carbon transformation of agriculture at the county level in a manner tailored to local conditions.