Climate change and human activities have caused various ecological risks to coastal urban agglomerations. Ecological security refers to the state of health of an ecosystem and its integrity. An objective and comprehensive evaluation of ecological security is significant for protecting the structure and function of coastal ecosystems. The driving force–pressure–state–impact–response (DPSIR) model was used to construct a dynamic simulation model of ecological security in the Xiamen–Zhangzhou–Quanzhou region (XZQR), located on the eastern coast of China. The ecological security level (ESL) characteristics of the spatial and temporal patterns were evaluated by calculating the ecological security index (ESI). Obstacle factors were analyzed as well. The results show the following: (1) From 2011 to 2021, the average ESI rose from 0.238 to 0.686 and went through a relatively insecure stage (2011–2015), a critical stage (2016–2019), and a relatively secure stage (2020–2021). (2) The ESI level in Quanzhou was higher in the early stage, and the level of ecological security in Zhangzhou showed a significant rising trend, increasing by 0.541. Its increase depended on increases in the impact layer. (3) The impact layer is the main obstacle layer affecting the ESL, and the main obstacles include CO₂ emissions (0.117), annual rainfall (0.091), general public budget expenditures (0.082), GDP growth rates (0.082), and green coverage in built-up areas (0.075). Therefore, we recommend promoting the complementary advantages of the XZQR and implementing ecological restoration projects.

Rapid regional development and intensified human activities increasingly disturb ecosystems, posing substantial threats to the integrity of large-scale ecological zones. As a World Natural Heritage site and a crucial national ecological zone, the Zhangjiajie Scenic Area plays a pivotal role in China’s environmental conservation efforts. To comprehensively assess tourism ecological security in the Scenic Area and strengthen the scientific basis for resource management and policymaking, this study developed a multi-dimensional ecological security evaluation system covering 2010–2024, incorporating dynamic changes in perturbation, reaction, and governance. Using entropy weight–TOPSIS and coupling coordination models, combined with obstacle degree analysis, we examined the temporal trajectory of ecological security and analyzed its underlying driving mechanisms. The study also examined factors influencing the sustainable development of the ecosystem. The results indicate the following: (1) Tourism ecological security in the Scenic Area followed a V-shaped trajectory of “rapid degradation—steady recovery—impact and rebound.” It declined sharply to an unsafe level between 2010 and 2014, steadily recovered from 2015 to 2019, briefly dropped in 2020, and then rebounded, reaching a peak evaluation value of 0.519 in 2024. (2) The co-evolution of perturbation, reaction, and governance subsystems has matured: their coupling coordination degree has increased annually and has remained at the level of “intermediate coordination” since 2020. The reaction subsystem plays a central role, serving as a bridge between perturbation and governance. (3) The driving factors exhibit a phased evolutionary pattern of “elements—facilities—structure—function.” Cultivated land area, total road mileage, and artificial afforestation area constitute the main long-term constraints. This research provides important insights for strengthening ecological security and sustainability in the Scenic Area while advancing regional ecosystem development. It also offers valuable guidance for ecological security management and policymaking in similar nature reserves.