Land cover change is a significant factor contributing to the variation in carbon sources and sinks in terrestrial ecosystem. Investigating the relationship between land use transition and carbon dynamics is crucial for optimizing regional land use planning and achieving sustainable development and the "dual carbon" goals. This study employed spatial analysis technology to analyze the temporal and spatial changes of carbon sources and sinks. By considering three future development scenarios, it predicted the future dynamics of carbon sources and sinks in Zhumadian City. The results showed that: (1) The net carbon emission of Zhumadian City had exhibited an increasing trend, rising from 268.13×10⁴ t in 2005 to 578.04×10⁴ t in 2020, with an increment of 309.91×10⁴ t. (2) Land use transitions in Zhumadian City involved a reduction in carbon stocks primarily due to the conversion of cropland to construction land and forestland to cropland, while the increase in carbon stocks primarily stemmed from the conversion of cropland to forestland and construction land to water area. (3) Applying the grey model and PLUS model, future spatiotemporal changes in land use and carbon dynamics in Zhumadian City were projected. The results indicated a continuous rise in net carbon emissions, although the rate of increase significantly slowed down under the scenario of cultivated land protection. Based on the preservation of cultivated land, Zhumadian City should restrain the expansion of construction land into ecological areas, expedite agricultural technological reforms, and foster low-carbon circular development.