Abstract: The green and low-carbon transformation of agricultural mechanization is an important component of the overall green transformation of agriculture, and relying on digital agriculture to address the traditional problems of high pollution and high energy consumption is of great significance. Based on panel data from 30 provinces in China from 2012 to 2022, this paper employs a fixed effect model and a threshold effect model to analyze the impact of digital agriculture on the green and low-carbon transformation of agricultural mechanization and its underlying mechanisms. The results indicate that digital agriculture can significantly promote this transformation and exhibits a threshold effect characterized by being stronger at the early stage and weaker at the later stage. Furthermore, this promoting effect is mainly realized through land transfer and green technology innovation, and shows clear regional heterogeneity between northern and southern regions as well as between grain-producing and non-grain-producing areas. Further analysis reveals that, compared with southern regions and major grain-producing areas, the promotion effect of digital agriculture is more significant in northern regions and non-grain-producing areas, with the non-grain-producing areas in the south performing the best. Based on these findings, it is suggested that the government accelerate the development of digital agriculture, continuously advance land transfer and green technology innovation, and place greater emphasis on enhancing the application level of digital agriculture in major grain-producing areas, so as to further strengthen its leading role in the green and low-carbon transformation of agricultural mechanization.