Cultivated land ecosystem,as essential semi-artificial and semi-natural ecosystems that support sustainable human development,have garnered significant attention in land use research due to their ecological efficiency and operational stability. This study integrates the input of natural emergy value and the output of ecosystem service value into an evaluation framework for the cultivated land use eco-efficiency (CLUE). Drawing on the analysis of natural emergy and ecosystem service values of cultivated land,the study using undesirable output Super-SBM model and the geographically and temporally weighted regression (GTWR) model to evaluate the ecological efficiency of cultivated land use and its determinants in the Chengdu-Chongqing Economic Circle from 2005 to 2020. The results show that:(1) Over time,the average CLUE in the Chengdu-Chongqing economic circle demonstrated a "slow increase" trend,with a significant rise from 0.698 in 2005 to 0.980 in 2020.(2) Regarding the spatial aspect,the average CLUE value in the Chengdu-Chongqing economic circle from 2005 to 2020 displayed a distribution characteristic of "elevated in the central and western regions and diminished in the east",with CLUE areas of lower value predominantly in Chongqing and those of higher value predominantly in the Chengdu-Chongqing economic circle. The difference in cultivated land availability caused by topography and landform is the main reason for the spatial heterogeneity of CLUE.(3) Between 2005 and 2020,the CLUE in the Chengdu-Chongqing economic circle was affected by various natural and socio-economic factors. Notably,sunshine duration and rainfall had adverse effects,whereas Per capita GDP,labor force,and the total power of agricultural machinery had beneficial effects on CLUE in Chengdu-Chongqing economic circle. The future of the Chengdu-Chongqing economic circle should focus on further improving agricultural production conditions,strengthening the construction of high-standard farmland and the level of agricultural mechanization,enhancing the cultivated land use eco-efficiency in the Chengdu-Chongqing economic circle,and promoting high-quality and sustainable development of agriculture.