With continuous progress in digital economy construction and smart city rollout, cutting-edge information technologies including IoT, big data, cloud computing and artificial intelligence have greatly changed how tourism industries operate. As a core direction for tourism digital transformation, smart tourism builds interconnected, data-led intelligent management systems. These systems can rationally allocate tourism resources, lift on-site service standards and boost daily operational efficiency for scenic sites. Even so, most domestic tourist attractions are still transitioning from basic digital informatization to full intellectualization, facing prominent obstacles: insufficient on-site data collection capacity, low efficiency when integrating disparate multi-source data, and a lack of precise personalized tourist services. As the core hub city of Hainan Free Trade Port, the maturity of smart construction at Haikou’s scenic spots directly shapes the high-quality growth of local tourism industries. Taking Haikou’s tourist sites as the research object, this paper sorts out the real-world progress of local smart tourism development and clarifies core functional demands for digital management platforms. A complete platform framework built around IoT sensing and multi-source data integration is proposed in this paper. The platform adopts a four-tier structural layout: sensing layer, data integration layer, intelligent decision layer and application service layer, which supports unified collection and comprehensive analysis of cross-category tourism data. Research outcomes prove that this framework can effectively raise data utilization efficiency and strengthen data-based management judgment capacity for scenic areas, offering practical technical references for digital upgrading of Haikou’s tourist attractions.