Clarifying the factors influencing CO2 emissions and their peaking pathways in major sectors holds significant practical importance for achieving regional dual-carbon goals. This paper takes Jiangxi, a less developed demonstration zone in central China, as an example. It pioneeringly combines the LMDI method, Tapio decoupling model, and LEAP model to multi-dimensionally analyze the driving mechanisms, evolution patterns, and dynamic relationships with the economic development of carbon emissions in Jiangxi’s key sectors from 2007 to 2021. It also explores the future carbon emission trends and peaking potentials of various sectors under different scenarios. Our results show that (1) Carbon emissions in various sectors in Jiangxi have continued to grow over the past fifteen years, and although some sectors have seen a slowdown in emission growth, most still rely on traditional fossil fuels; (2) Economic growth and industrial structure effects are the main drivers of carbon emission increases, with a general trend towards decoupling achieved across sectors, while agriculture, forestry, animal husbandry and fishery, and ferrous metal smelting have shown a decline in their decoupling status; (3) In the carbon reduction and low-carbon scenarios, the carbon emission peaks in Jiangxi are estimated to be 227.5 Mt and 216.4 Mt, respectively, and targeted strategies for high-emission industries will facilitate a phased peak across sectors and enhance emissions reduction benefits. This has significant reference value for the central region and even globally in formulating differentiated, phased, sector-specific carbon peaking plans, and exploring pathways for high-quality economic development in tandem with ecological civilization construction.