Abstract: In the context of innovation-driven and low-carbon strategies, assessing the role of agricultural green technological innovation in reducing carbon emissions under environmental regulations is essential for strengthening green technological capability, refining policy design, and advancing sustainable agricultural development. Using panel data from 31 provinces (autonomous regions and municipalities, excluding Hong Kong, Macao, and Taiwan) from 2001 to 2022, this study applied a panel threshold regression model to investigate how agricultural green technology innovation influenced carbon emissions reduction, with particular attention to the moderating role of different types of agricultural environmental regulation. The findings suggested the following: 1) The improvement of agricultural green technology innovation helped reduce agricultural carbon emissions; in particular, pollution prevention-oriented innovations played a greater role than resource conservation innovations in reducing agricultural emissions. This indicated that the structural characteristics of technological innovation had a significant impact on agricultural emission-reduction pathways. 2) Agricultural environmental regulation significantly reduced agricultural carbon emissions, although with a policy lag. Resource conservation-oriented regulation exerted a stronger direct effect on emissions reduction. 3) Agricultural environmental regulation and its subtypes (resource conservation and pollution prevention) all exhibited single-threshold effects. In particular, resource conservation-oriented and pollution prevention-oriented regulations could more effectively activate the potential of agricultural green technology innovations for reducing agricultural carbon emission, due to their lower thresholds and greater efficiency. This implied that strengthening environmental regulations further stimulated agricultural green technology innovation and reduced carbon emissions, while the precise alignment between differentiated regulations and green innovations enhanced emission-reduction effects, thereby confirming that the Porter Hypothesis remained valid in the agricultural sector. Moreover, the single-threshold effect indicated that China’s current agricultural environmental regulations remained within a moderate range, effectively promoting green agricultural technological innovation and advancing green agricultural development. Based on these findings, policymakers should actively promote green agricultural technological innovations, particularly in the development, dissemination, and adoption of pollution prevention technologies. At the same time, more emphasis should be placed on strengthening resource conservation-oriented environmental regulations and improving the legal and regulatory framework for agricultural environmental protection to accelerate the transition toward low-carbon and sustainable agriculture.