Marine plastic waste pollution damages the stability of the marine ecosystem and inhibits the sustainable development of the "blue economy", which has aroused widespread concern worldwide. Nowadays, cooperation on marine plastic waste management is an urgent research topic. A global consensus on management cooperation is emerging, but the economic feasibility of cooperation has not yet to be proven. This paper takes the amount of capital investment, technology level of governance and the amount of marine plastic waste to be treated as variables affecting the cooperative income to construct a cooperative network game model for marine plastic waste management from the perspective of economics. The paper distributes benefits based on the "Myerson value", analyzes the equilibrium conditions of the model and tests the stability of cooperation. In addition, numerical analysis is carried out using actual data from key countries to demonstrate the practical economic feasibility of cooperation in marine plastic waste management. The findings include: (1) The technology level of governance and the amount of marine plastic waste to be treated have a negative impact on the country's choice of cooperative governance strategies and the stability of cooperative alliance, while the amount of capital investment is conductive to it. (2) The size of the alliance has an impact on country's strategic choices and the stability of the alliances. Too small an alliance is not conducive to cooperative alliance building, which gradually becomes more likely as the size of the alliance increases, but it is uncertain the effect of oversized alliance and what size is most appropriate. (3) Cooperation in marine plastic waste management is economically feasible at both the theoretical and practical levels. (4) Encouraging technological innovation to improve the governance level, implementing extended producer responsibility measures to shift the management cost, exerting the positive influence of key countries to promote the stability of the alliance, and establishing a reasonable interest adjustment mechanism to coordinate the interests of all parties are helpful to build a stable and efficient cooperation alliance and improve the economic feasibility of marine plastic waste management cooperation. This paper not only provides theoretical support for the global cooperation of marine plastic waste management, but also proves the feasibility of practice and points out the direction for its practice.