As an important institutional innovation in modern environmental rule of law, marine environmental public interest litigation undertakes the core mission of safeguarding the public interest of marine ecology and balancing the governance efficacy of multiple actors. In the context of ecological civilization construction, the fluidity, complexity, and systemic characteristics of the marine ecological environments pose severe challenges to conventional relief mechanisms. Confronting the operational dilemmas of multiple relief mechanisms and the practical challenges to relief effectiveness in marine environmental public interest litigation, it is imperative to adopt collaborative governance as the core conceptual framework, thereby constructing an integrated institutional optimization encompassing "preventive, substantive, and procedural" dimensions, including: enhancing the preventive function of administrative licensing, clarifying the boundaries of prosecutorial supervision intervention, and strengthening risk prevention and control; improving the marine ecological environment damage compensation system, clarifying the standards for determining ecological restoration responsibilities, and enhancing relief effectiveness; designing a hierarchical litigation priority system, innovating non-litigation connection mechanisms, and consolidating procedural safeguards. Therefore, the systematic protection of marine environmental public interests can be achieved, providing theoretical support for enhancing the modernization of environmental governance and advancing the development of marine ecological civilization.