Against the backdrop of rapid industrialization and urbanization, cropland abandonment has emerged as a major challenge threatening global food security and constraining the sustainable development of agriculture. Endowed with earmarked funds and the characteristic of inclusive benefits, farmland water conservancy project can directly improve agricultural production conditions, therefore help address the issue of cropland abandonment and provide crucial support for consolidating the foundation of food security. Thus, this chapter employs unbalanced panel data from the 2017 and 2019 China Rural Household Panel Survey (CRHPS) and adopts a panel two-way fixed effects (TWFE) model to empirically examine the impact of farmland water conservancy project on cropland abandonment. Results show that farmland water conservancy project facilities significantly curbed cropland abandonment, resulting in a 7.5% decrease in the average abandonment rate among farming households. This effect is primarily achieved through channels such as increasing agricultural production income and reducing production and transaction costs. However, this effect is also moderated by household resource endowments and regional economic development, both of which lead to heterogeneity in the suppression impact of the projects. Specifically, among households with higher agricultural dependency, less per capita arable land, and villages in economically underdeveloped areas or farther from county seats, farmland water conservancy project facilities exert a more pronounced suppression effect on cropland abandonment, while this stronger effect is not observed among other households and villages. Based on these findings, this study proposes focusing on the role of water conservancy facilities, blocking the conditions that lead to cropland abandonment, and tailoring measures to local conditions and individual households. This approach will help achieve the organic integration of sustainable agricultural development and food security.