Abstract:The importance of knowledge-sharing behavior in major engineering projects has been widely recognized, but in practice, limited by the complexity of projects and organizations and strict time and cost, the knowledge-sharing behavior of across organizations cannot be effectively implemented and managed. To enhance the precision in managing major engineering projects, improve the specificity of stakeholder management, and offer new insights for high-quality development in the construction industry, this paper combines stakeholder theory, rational behavior theory, and organizational learning theory, establishes a multi-level project behavior analysis architecture from the macro, micro and practical levels, provides perspectives and tools for understanding inter-organizational behaviors in the complex backdrop of projects across different scales. Based on this, empirical analysis is conducted by collecting data through questionnaire surveys, specifically focusing on a typical representative of major engineering projects, the large aeronautic hub projects, and a total of 291 questionnaires are collected, primarily from several large aeronautic hubs in China, and then the mechanism by which key stakeholders' knowledge-sharing behaviors affect project performance is explored. The results indicate that within this multi-level theoretical framework, stakeholders' perceived attitudes towards benefits, subjective norms, and institutional support have a significant positive impact on their intentions towards knowledge-sharing behavior, furthermore, the intention to share knowledge significantly and positively impacts actual knowledge-sharing behavior, which in turn significantly enhances the performance of large aeronautic hub projects. Therefore, in the implementation process of major engineering projects, in addition to relying on traditional hard management methods, attention should also be given to soft management aspects(such as organizational behavior, cultural atmosphere, etc.). By identifying and optimizing the inter-organizational behavior patterns of stakeholders, the performance of the project can be effectively improved.