Abstract: Under the background of ‘double carbon’, land right confirmation is regarded as a powerful measure to promote agricultural carbon emission reduction. By exploring the mechanism of land right confirmation on agricultural carbon emission, it provides practical experience for agricultural carbon emission reduction, so as to help achieve the goal of ‘double carbon’. Based on the panel data of 30 provinces and cities in China from 2008 to 2021, the FGLS model is used to evaluate the impact of land rights confirmation on agricultural carbon emission reduction. The results show that land right confirmation has a promoting effect on agricultural carbon emission reduction, and its influence has an inverted U-shaped structure. Land right confirmation reduces agricultural carbon emissions by promoting agricultural mechanization, that is, there is an impact mechanism of land right confirmation-promoting agricultural mechanization-agricultural carbon emission reduction. Land titling has significant regional heterogeneity on agricultural carbon emissions in different agricultural functional areas. It has a significant effect on agricultural carbon emission reduction in major grain-producing areas, but no significant effect on carbon reduction in non-major grain-producing areas. Therefore, it is necessary to continuously optimize the land right confirmation policy and give full play to its agricultural carbon emission reduction effect, to promote the progress and innovation of agricultural technology, and to improve the socialized service system of agricultural machinery, the local governments implement differentiated land rights confirmation policies according to local conditions.