Exploring the relationship between new urbanization and agricultural carbon emission is of great significance to promote the green and low-carbon development of agriculture. The urbanization level was comprehensively assessed by constructing an index system, and the agricultural carbon emission efficiency was measured using the SBM model, and finally, the relationship between urbanization and agricultural carbon emission efficiency was quantitatively analyzed with the help of the PVAR model. The results of the study show that：(1) From a general point of view, new urbanization is the Granger cause of agricultural carbon emission efficiency, and new urbanization has a reverse effect on the improvement of agricultural carbon emission efficiency, while the opposite is not true. (2) Agricultural urbanization is always the Granger cause of agricultural carbon emission efficiency in both main grain-producing and non-main grain-producing areas, but the inhibitory effect of new urbanization on the improvement of agricultural carbon emission efficiency is significantly stronger in main grain-producing areas.