On August 24, 2023, the discharge of nuclear-contaminated water from Fukushima into the ocean, an action that has sparked widespread concern and apprehension within the international community, particularly among nations in the Asia-Pacific region. This issue transcends mere environmental concerns, touching upon transnational cooperation and regional policy coordination. The strategic significance of the Asia-Pacific region in international studies is underscored by the concentration of multiple national powers engaging in complex strategic games to achieve their respective national interests and objectives. This paper aims to outline the context of nuclear wastewater discharge, analyze the potential environmental risks, and explore the threats to the marine ecological safety of neighboring countries. It discusses how this decision has become both a challenge and an opportunity for cooperation among Asia-Pacific nations in terms of environmental protection and marine ecological safety. Additionally, the paper employs the Graph Model for Conflict Resolution (GMCR) method, based on existing multilateral cooperation frameworks such as regional marine cooperation organizations and international legal norms, to study the challenges and opportunities for regional cooperation in the context of nuclear wastewater discharge. This research may offer insights and guidance for mitigating current threats to marine ecological safety in the Asia-Pacific, and for constructing a more sustainable and resilient regional marine governance structure.