As a typical eco-friendly technology, water-saving technology can not only effectively alleviate the pressure of tightening resource and environmental constraints, but also promote farmers to increase efficiency and income. It is an important means to promote the process of rural revitalization and green transformation of agriculture in China. Based on a field survey data of 450 households in 2022, this article conducted an in-depth analysis of the relationship between the fragmentation of agricultural land and the adoption and sustained adoption behaviors of water-saving technologies among farmers by the Oprobit model and Biprobit model. Results show that: 1) Farmland fragmentation has a negative impact on farmers’ adoption of water-saving technologies and their persistence in adopting them, but has a positive marginal effect on the continued adoption of agronomic water-saving technologies alone; 2) The synergistic effect generated by farmers in collective irrigation actions can significantly promote the improvement of farmers’ adoption of water-saving technologies, and has a significant incentive effect on the sustainability of farmers’ adoption of engineering water-saving technologies; 3) Government support can effectively break the endowment constraints in the process of farmers’ adoption of water-saving technologies, and reduce the adverse effects of farmland fragmentation; 4) Social networks can restrict the negative effect of agricultural land fragmentation on farmers’ adoption of water-saving technologies. The degree and persistence of farmers’ adoption of water-saving technologies increase with the expansion of social network size. Based on the above results, this paper suggests improving farmland irrigation facilities, providing systematic training on water-saving technology for farmers, and giving full play to the supporting and guiding role of the government.