<p>Ecological security involves the protection and maintenance of ecosystem stability, encompassing climate adaptation, sustainable resource utilization, biodiversity conservation, and the effects of ecosystem conditions on human well-being. The limitations in evaluation methods and understanding of mechanisms hinder the accurate assessment and reliability of ecological security evaluations. This research has established a comprehensive assessment model grounded in ecosystem structure and function, aiming to develop a scientific framework for assessing ecological security and to systematically investigate its driving mechanisms. This framework integrates remote sensing and multi-source data and systematically evaluates the spatiotemporal changes in ecological security in the Poyang Lake City Group during the years 2010, 2015, and 2020. It is grounded in three dimensions: ecosystem health, vulnerability, and services. Research shows that the comprehensive ecological security index declined sharply, with the regional ecological security status primarily characterized as moderate safety. The study found that ecological security status is significantly positively correlated with ecosystem health, vulnerability, and ecosystem services, with precipitation emerging as the dominant driver of ecological security dynamics. The study’ s results possess significant theoretical importance and practical value, important for guiding regional ecological conservation planning and advancing sustainable environmental resource management. They also offer valuable insights for addressing climate change and biodiversity conservation, providing scientific evidence for the long-term sustainability of ecosystems.</p>