As a crucial element in safeguarding regional ecological security and enhancing human well-being, the ecological security pattern constitutes a core component of the overall territorial spatial pattern. However, influenced by factors such as planning concepts and technical approaches, existing ecological security pattern source identification results often manifest as large, contiguous, and concentrated natural ecological patches (such as large forests and grasslands), while overlooking small, scattered semi-natural lands in residential and production areas that provide localized ecosystem services. Although large ecological patches with superior natural conditions make significant contributions to maintaining regional ecological security levels, these areas are typically distributed in natural zones with low population density. This not only creates a spatial mismatch with populated residential areas where social groups concentrate, but also leads to difficulties in aligning conservation objectives with social needs. Consequently, this results in a supply-demand misalignment in the ecological security pattern, characterized by spatial non-overlap and typological mismatch between supply and demand. In response, this study builds upon existing construction methods and, from the perspective of production-living-ecological space differentiation, carefully considers the Pareto efficiency (optimal cost-benefit ratio) of spatial demands and conservation actions within the region, proposing a research framework and technical approach to address the supply-demand misalignment in ecological security patterns. First, it establishes a method for delineating the scope of production-living-ecological functional spaces, then references the Common International Classification of Ecosystem Services (CICES) to determine the required ecosystem services matching each functional space, and further employs Zonation5 to identify multi-functional ecological source protection priorities within the three functional spaces. Finally, it incorporates two constraint conditions from realistic scenarios—costs (expenses for creating and maintaining green spaces) and benefits (the effective radiation range of source protection)—to develop a Pareto-optimal solution identification method that achieves the best cost-benefit ratio. The method was further applied and analyzed using Xi'an city—a pilot city for territorial spatial ecological restoration planning—as a case study. Results indicate that the optimal ecological security pattern comprises 692 ecological source areas and 689 critical ecological corridors, achieving a total input cost to total conservation benefit ratio of 0.637. Among 164 multi-scenario schemes in this study, this represents an ideal solution that balances ecosystem service demands across production, living, and ecological spaces while maintaining cost-effectiveness. Compared to construction results from previous studies, it better accommodates local demands. This research aims to provide insights into resolving the prevalent supply-demand misalignment in ecological security patterns, with the goal of enhancing the scientific validity and implementation feasibility of ecological security pattern construction.