Developing low-carbon urban agglomeration is the best way to achieve "carbon peaking" and "carbon neutrality" goals under the background of rapid urbanization. Based on carbon emissions accounting, the Tapio decoupling model and the Logarithmic Mean Divisia Index (LMDI) method are utilized to analyze the decoupling status and driving mechanisms of carbon emissions of the Golden Triangle of Southern Fujian (GTSF), Xiamen, Zhangzhou and Quanzhou. The main findings are as follows:(1) Carbon emissions and carbon emissions per capita both kept increasing from 2005 and 2017, with the same trend. Quanzhou, an industrial center of the GTSF, has the highest carbon emissions and carbon emissions per capita. Zhangzhou, a developing city, has the least carbon emissions but the highest growth rate of carbon emissions and carbon emissions per capita. Xiamen, a service-oriented city, holds the lowest growth rate of carbon emissions. (2) Decoupling status of the GTSF has improved. The average decoupling index of the GTSF is 1.03, and the decoupling status is dominated by the expansive connection. The average decoupling indices of Xiamen, Zhangzhou and Quanzhou are 0.45, 2.70 and 1.10, respectively. The dominant decoupling status of the three cities is weak decoupling, expansive negative decoupling, and the expansive connection, respectively. (3) Gross domestic product (GDP) per capita and population size are positive factors of carbon emissions of the GTSF, while energy structure and energy intensity are negative factors. The contribution of the positive factors is decreasing, while the contribution of the negative factors is increasing. GDP per capita and energy structure have the strongest promoting effects and inhibiting effects on carbon emissions of Zhangzhou and Xiamen, respectively. The effects of energy intensity on carbon emissions of the three cities are different. (4) Population expansion leads to an increase in carbon emissions, which is not conducive to the decoupling of carbon emissions and economic development. Population size has no decoupling efforts on carbon emissions reduction of the GTSF. The optimization of energy structure and the decline of energy intensity contribute to the decoupling of carbon emissions and economic development. Energy structure and energy intensity are the strong decoupling efforts and the weak decoupling efforts of carbon emissions reduction of the GTSF, respectively. Energy intensity has no decoupling efforts on carbon emissions reduction of Quanzhou. For the GTSF, optimizing energy structure is the key to realize carbon emissions reduction and "carbon peaking and neutrality" goals. It is suggested that Xiamen, which has been decoupled, should formulate carbon emissions peaking action plans, and lead the peaking actions of the GTSF. Zhangzhou can achieve carbon emissions reduction by upgrading industrial structure. Carbon emissions reduction of Quanzhou depends on the improvement of energy efficiency.