<p>Enhancing energy eco-efficiency (EEE) is essential for addressing the global energy crisis and mitigating climate change, contributing to the sustainable development of human society. However, most studies have focused on the role of influencing factors without exploring their underlying influence mechanisms. In this paper, the Malmquist-Luenberger index is utilized to measure EEE in Jiangsu Province, providing a dynamic evaluation of EEE from both temporal and spatial perspectives. An econometric model is employed to analyze the internal mechanisms of each influencing factor. Results show that: (1) EEE in Jiangsu Province shows a trend of “negative, positive, then negative” from 2008 to 2020, with technological progress being the main driver and substantial regional growth differences. (2) The effects of openness to the outside world, industrial structure, economic development level, and urbanization on EEE exhibit significant regional heterogeneity, but the technological level generally promotes EEE. (3) Jiangsu Province as a whole and Central Jiangsu display a single improvement path, which is driven by technological progress and technical efficiency, respectively. In contrast, the improvement paths in Southern and Northern Jiangsu are more diverse and can be promoted through both technical efficiency and technological progress. The study expands the theoretical research framework and index system of EEE, emphasizing the need to identify driving forces and influencing mechanisms for EEE improvements across different regions, thereby proposing practical and differentiated paths to boost regional EEE and facilitate regional green and low-carbon development.</p>