Abstract: Sustainable intensification of cultivated land use provides a new research paradigm for addressing the contradiction between food security and resource and environmental constraints. This study employs the energy accounting method to measure the input-output flow in cultivated land use in Jiangxi Province from 2001 to 2021, assessing the level of sustainable intensification of cultivated land use (SICLU). Additionally, principal component analysis is used to explore the degree of coordination between SICLU and the level of socio-economic development. The results indicate that: 1) From the input-output perspective, the net loss of topsoil during cultivated land use is 1.75 times greater than the resilience of the cultivated land system, placing significant pressure on land protection. Agricultural output and waste discharge increased by 38.59% and 21.75%, respectively. 2) The energy productivity rate (EPR) and energy yield rate (EYR) of the cultivated land ecosystem in Jiangxi Province increased by 32.86% and 35.52%, respectively. The environmental load ratio (ELR) decreased by 13.19%, while environmental economic efficiency (EE) rose by 9.07%. Throughout the study period, emergy productivity in each prefecture-level city remained above 5.45. The emergy output rate fluctuated between 5.51 and 18.74 (excluding Nanchang City), with ELR fluctuating between 1.64 and 5.78, and EE ranging from 0.30 to 1.09. 3) The SICLU index in Jiangxi Province displayed a fluctuating upward trend, peaking at 33.70 in 2020, reflecting an overall increase of 24.26%. All prefecture-level cities showed an increase, with the spatial pattern remaining unchanged, progressing from southwest to northeast. 4) Although SICLU levels are not aligned with socio-economic development levels, the influence of socio-economic development on SICLU is becoming increasingly evident. It is recommended that relevant departments optimize the input structure of the cultivated land system to reduce topsoil loss, improve crop planting structures and spatial layouts, and enhance the ecological compensation system. Localized strategies should be implemented to promote the coordinated development of SICLU and socio-economic progress.