The balance between supply and demand of ecosystem services is the basis for guaranteeing ecological security. Integrating the mechanism of ecosystem service supply and demand into the construction of ecological security pattern is of great significance for guaranteeing regional ecological security and enhancing human ecological well-being. Based on the principles of landscape ecology, this study first clarifies the flow mechanism of ecosystem service supply and demand roles in social-ecological systems, and then proposes the goal of constructing an ecological security pattern of coupled ecosystem service supply and demand. Further, this study also identifies methods for constructing ecological security patterns that couple the supply and demand of ecosystem services. In addition, this study constructs a landscape ecological security pattern and a social ecological security pattern using the Southern Jiangsu Province region as the study area to empirically validate the proposed logic and methodology. The results show that: 1) the process of ecosystem service provisioning from generation to transmission to consumption into human ecological well-being constitutes a complete flow mechanism of ecosystem service supply and demand roles. The ecological security focuses on ecosystem services and ecological risks, while human ecological well-being is dependent on active human access and ecosystem service flow. Therefore, the ecological security pattern that couples the supply and demand of ecosystem services should be constructed with the goal of maintaining regional ecological security and safeguarding regional human ecological well-being; 2) The supply and demand of ecosystem services in southern Jiangsu Province presents a mismatch pattern of "high in the south and low in the north" and "high in the north and low in the south". On the basis of which 4247.46 km² of ecological sources, 1882.16 km² of demand sources, 1614.02 km of ecological corridors, 1915.82 km of supply-demand corridors, 29 ecological pinch points, 23 ecological barrier points, and 20 ecological nodes of supply-demand are identified; 3) Taking the source areas as the functional core, the corridors as the connecting carrier, and the nodes as the key hub, this study proposes an optimized layout of the social-landscape ecological security pattern of "three zones, four belts and two clusters", and on this basis puts forward a number of targeted protection and restoration strategies, in the hope of achieving the goal of promoting the synergistic development of economic and ecological space. The study can enrich the theories and methods of constructing regional ecological security patterns, and provide scientific references and lessons for promoting the optimization and control of territorial space.