<p>The fragmentation of land use patterns presents a prominent spatial characteristic in global land-use change and agricultural intensification processes, yet its impacts on regional carbon balance and the underlying mechanisms remain poorly understood. Focusing on the Using the Central Liaoning Urban Agglomeration, this study employs multi-source remote sensing data and statistical information to establish a framework for assessing both cultivated land fragmentation indices (CLFI) and carbon accounting. Land cover data are utilised to construct indices of cultivated land fragmentation (CLF) and carbon stock indicators, whilst carbon emissions are calculated based on land cover patterns and energy statistics. This approach characterises the spatiotemporal evolution of carbon emissions, carbon stocks, and CLF within the study area. A coupling coordination model quantitatively assesses the coordination between CLF and carbon emissions and storage, while scenario simulations explore pathways to optimize this coordination. The results show that regional carbon emissions have continued to rise, whereas carbon storage has generally declined, with the carbon system shifting from a storage-dominated to an emission-dominated regime. CLF shows significant correlations with both carbon emissions and carbon storage, and the coordination state displays an “east-high, west-low” spatial pattern. Scenario simulations further indicate that differences among scenarios reshape the coordination between CLF and carbon dynamics, with the ecological protection scenario consistently outperforming the others. This study provides scientific support for implementing differentiated land-use management in similar regions to achieve the dual goals of cultivated land conservation and regional carbon balance.</p>