Abstract: The carbon metabolism system of cultivated land involves a large-scale, high-frequency carbon budget, which profoundly impacts the land-use carbon cycle. In the context of carbon neutrality goals, studying the characteristics of change in carbon metabolism density of cultivated land and the corresponding influencing factors can help expand our understanding of carbon metabolism. This study may provide a scientific basis for the sustainable development of cultivated land and land-use carbon reduction. Therefore, this study took Jiangsu Province as an example, and analyzed the characteristics of change in carbon metabolic density of cultivated land from 2000 to 2020. The metabolism density analysis from ENA was performed, and the primary drivers affecting carbon metabolism were identified. The spatial autocorrelation and geographically weighted regression models were used in this study. Our research revealed the following key findings: (1) The average carbon metabolism density of cultivated land in Jiangsu Province from 2000 to 2020 was 3336.06 t/km2, and the overall trend of carbon metabolism density of cultivated land showed a noticeable increase. (2) The spatial variation of carbon metabolism density was evident, with higher carbon metabolism density in economically underdeveloped areas and lower carbon metabolism density in economically developed areas. (3) The carbon metabolism density demonstrated a significant positive spatial correlation, characterized by spatial clustering of low-low or high-high values. This spatial positive correlation intensified over time. (4) Multiple factors influenced the change in the carbon metabolic density. The multiple cropping index and average annual precipitation had positive effects, while the average fertilizer use per mu and the level of fiscal support for agriculture had adverse effects. The average annual temperature exhibited a bidirectional regulatory effect, alternating between positive and negative influences. The carbon metabolism density effectively illuminated the complexity and dynamics of carbon cycles in cultivated land ecosystems, clearly illustrating how land use practices and management strategies dynamically modulated carbon inputs and outputs. Optimization of land management can effectively balance carbon inputs and outputs, which is crucial for achieving the dual carbon goals.