<p>This study examines the complex relationships between institutional trust, psychological synergy effects, and cooperation outcomes in China-Central Asia partnerships using structural equation modeling. Based on survey data from 671 cooperation practitioners across China and five Central Asian countries, the research tests a comprehensive theoretical framework that integrates institutional and psychological perspectives on cross-cultural collaboration. The findings reveal that institutional trust significantly enhances cooperation effectiveness through both direct pathways and indirect mechanisms mediated by psychological synergy effects. Cultural distance moderates the relationship between institutional trust and psychological synergy, with formal mechanisms becoming more critical when cultural differences are substantial. Our analysis across multiple referent domains reveals that the strength of these relationships varies when respondents evaluate individual behaviors, organizational practices, and systemic environments. This pattern suggests that building effective partnerships calls for attention to how practitioners at different operational scopes perceive institutional arrangements and psychological coordination. These results offer evidence-based guidance for policymakers and practitioners seeking to design more effective China-Central Asia cooperation frameworks by addressing both institutional infrastructure and psychological coordination mechanisms in tandem.</p>