As a key candidate for the proposed Changdao National Park in northern China's Changdao County, Daheishan Island faces ecological and socioeconomic crises from unregulated commons exploitation. This proposal employs participatory governance and Nature-based Solutions (NbS) to restructure the island's commons through systematic redesign, enhancing land-use efficiency and generating sustainable economic returns. The framework concurrently addresses ecosystem degradation, livelihood sustainability, and demographic decline mitigation.