Abstract: The development of cultivated land reserves serves as a critical measure for ensuring food security and achieving the requisition-compensation balance of cultivated land. In ecologically vulnerable areas, this development process should integrate ecological conservation and sustainable resource utilization. However, conventional research paradigms have always neglected ecological security constraints. Based on the minimum cumulative resistance (MCR) model, this study identified the ecological and construction source areas in Taonan City, Jilin Province. Accordingly, the ecological security pattern in this city was established, including core ecological zones, ecological buffer zones, agricultural development zones, and urban construction zones, thereby defining the priority zones for ecological conservation. Furthermore, using the comprehensive weighting method, which combines the principal component analysis (PCA) and the analytic hierarchy process (AHP), an assessment system comprising 11 indicators was developed across three dimensions: natural background, ecological constraints, and development conditions. Following the determination of the weights of all indicators, the development potential of cultivated land reserves was assessed. The results show that the ecological security pattern zoning map assisted in effectively identifying the priority zones for ecological conservation and development, thereby accurately delineating the ecological red line for the development of cultivated land reserves. Taonan City holds 199.55 km² of developable cultivated land reserves, with their development potential categorized into three classes: high potential (56.72 km²), medium potential (94.54 km²), and low potential (48.29 km²). The development zones with low-to-medium potential are primarily distributed in Xiangyang and Erlong townships, while those with medium-to-high potential are principally located in northwestern Datong Township and southeastern Jiaoliuhe Township. The comprehensive weighting method effectively balanced the effects of subjective experience and objective data on weight allocation, thus ensuring scientific indicator weights and reliable assessment results. These findings provide a scientific basis for developing cultivated land reserves and formulating differentiated strategies in ecologically vulnerable areas, holding practical significance for ensuring food and ecological security.