<p>In the future, an increasing number of integrated energy systems in parks are expected to participate in cooperative games to leverage transactional collaboration among multiple stakeholders and the interaction between various energy sources. Consequently, it is essential to fairly distribute the cooperative benefits of multi-park integrated energy systems. This paper introduces a gain allocation strategy for multi-park integrated energy systems based on cooperative games and an enhanced Shapley value method. The strategy involves establishing a cooperative game model for multi-park integrated energy systems with single-park integrated energy systems as participants. By considering comprehensive costs including energy purchase, operation and maintenance, and transmission loss, the traditional Shapley value method is improved, adhering to principles of overall and individual rationality. The improved Shapley value not only takes into account the contributions of each participant but also includes the costs incurred and risks borne by the participants. This makes the benefit distribution fairer and more realistic. Additionally, it is more scalable and can be applied in more complex practical scenarios. Through case analysis, it was found that the improved Shapley value method reallocates the benefits of the integrated energy systems across various parks. The improved Shapley value method reduced the costs for residential park by 5.86%, increased the costs for commercial park by 3.22%, and raised the costs for industrial park by 4.34%. This has achieved a synergistic effect among the entities, improved resource utilization, and made the benefit distribution within the alliance more rational and balanced.</p>