[Objective] The land use carbon emissions in Jiujiang City, Jiangxi Province were quantitatively measured, and its temporal and spatial evolution characteristics, and the risk of land use carbon emissions were determined in order to provide a scientific reference for the construction of green and low-carbon land use methods in Jiujiang City. [Methods] Land use carbon emissions, and their temporal and spatial variation characteristics in Jiujiang City from 2000 to 2020 were measured by the carbon emission coefficient method. The carbon emission risk of each county was identified by the carbon emission risk index based on grid perspective. The factors influencing land use carbon emissions were analyzed based on the logarithmic mean divisia index (LMDI) model. [Results] Net carbon emissions from land use in Jiujiang City have been increasing at an average annual rate of 13.75% during 2000—2020. Construction land was the main carbon source, accounting for more than 90% of the carbon emissions, whereas forest land was the main carbon sink. Additionally, net carbon emissions in Jiujiang City presented a spatial distribution pattern of “high in northeast and low in southwest”. Wuning County and Xiushui County have good forest coverage and have always been carbon sinks. Lianxi District, Xunyang District, Hukou County, and Ruichang City, with more construction land, had the largest net carbon emissions and accounted for more than 95% of carbon emissions in Jiujiang City. Moreover, the carbon emission risk from land use in Jiujiang City was generally low, and showed a distribution pattern of “high in northeast and low in southwest”. High carbon emission risk areas were Lianxi District, Xunyang District, and Chaisang District, all along the Yangtze River. Economic development level was the main factor increasing carbon emissions, while energy consumption intensity was the key factor curbing carbon emissions. [Conclusion] Carbon emissions from land use have increased significantly during 2000—2020. New carbon source land use should be controlled, land use structure should be optimized, a low-carbon, green-energy utilization system should be actively constructed, and “Jiujiang model” construction of green and low-carbon development should be promoted in the Yangtze River Economic Belt.