Abstract: Taking Yunnan Province as a case study, this study constructed four ecosystem service indicators, namely water yield, soil conservation, habitat quality, and carbon storage. An ant colony optimization (ACO) algorithm was employed to identify ecologically valuable potential protected areas in 2021. The PLUS model was further integrated to simulate land-use patterns and ecosystem service dynamics under four policy-oriented scenarios in 2035, including natural development, ecological priority, cultivated land protection, and urban expansion. The results showed that the identified potential protected areas had an overlap rate of 41.8% with existing protected areas and were mainly concentrated in southern and southeastern Yunnan. After incorporating these areas as development constraints, the ecological priority scenario exhibited the best overall performance in ecosystem services. Specifically, carbon storage reached 4.7 × 10⁹ t, the highest mean habitat quality was 0.53, and soil conservation reached 2.8 × 10¹⁰ t, representing increases of 2.0 × 10⁷ t, 0.01, and 3.0 × 10⁷ t, respectively, compared with the natural development scenario. In contrast, the cultivated land protection scenario achieved the highest water yield, reaching 7.5 × 10¹⁰ m³.