With the comprehensive implementation of China’s “Digital China” strategy, digital technologies have become deeply integrated into various economic sectors. As a vital component of the modern service industry, the tourism sector is experiencing a profound transformation toward digitalization and intelligent development. This paper explores the synergistic mechanisms of tourism investment policies under the guidance of the national digital strategy. Centered on multi-level governance and cross-departmental collaboration, the study investigates how various policy tools—such as fiscal support, financial instruments, land planning, and digital platforms—interact and coordinate in practice. Through a combination of policy text analysis, case studies, and theoretical modeling, the study constructs a comprehensive evaluation framework that measures policy synergy across dimensions of goal alignment, resource integration, coordinated implementation, and feedback mechanisms. Empirical evidence from regions like Hainan and Zhejiang demonstrates that effective policy coordination significantly enhances investment performance and promotes innovation in tourism development. The study concludes that achieving high-quality investment in the tourism sector requires not only coherent policy objectives and supportive infrastructure but also digital governance capabilities and a responsive institutional environment. Finally, targeted policy suggestions are offered to enhance the effectiveness and sustainability of tourism investment policy systems in the digital era.