Based on a case study of the Ant Alliance Retail Ecosystem, this study adopts the ecosystem orchestration perspective to systematically explore the mechanisms through which value co-creation is realized. The findings reveal that alliance-led industrial ecosystems exhibit a three-layer nested structure, wherein the core organization layer, alliance member layer, and ecosystem periphery layer interlock to form the foundation for multi-actor interaction; alliance organizations achieve integrative, interactive, and complementary value co-creation with participants across different layers via ecosystem orchestration; as a distinctive demand-side subject, alliances demonstrate significant differences from other demand-side actors across multiple value co-creation dimensions.