In this study, we use the modified gravity model and social network theory to analyze the spatial structure and characteristics of the tourism economic connections among cities in the Guangdong-Hong Kong-Macao Greater Bay Area from 2008 to 2016 and propose a new cooperation model and some strategies to enhance the tourism economy in the region. The results show that first, the number of tourism economic links in the Guangdong-Hong Kong-Macao Greater Bay Area grew rapidly, and the links between particular cities strengthened, especially those between Guangzhou and Foshan, Macao and Zhuhai, and Hong Kong and Shenzhen. Second, the node centrality of the overall tourism economic network in the study area increased, indicating that the tourism economic network among the 11 cities in the Greater Bay Area gradually shifted from a multi-core structure toward a network structure. In terms of the direction of flow of tourism economy, Guangdong, Hong Kong, and Macao are outflow cities of tourism resources, while the other eight cities are inflow cities, indicating that the diffusion effect exceeds the linkage effect over the entire network. Third, the tourism economic links in the Greater Bay Area increased in strength, resulting in increased network density. There are obvious hierarchical differences between the core and edge areas in the network structure, which can be divided into three agglomerating subgroups: Guangzhou-Foshan, Hong Kong-Shenzhen-Dongguan, and Zhuhai-Zhongshan-Macao. Finally, based on the concept of "collaborative hierarchical network development", we propose a "tourism city center-tourism city cooperation circle-tourism global destination network" path to enhance tourism economic cooperation in the study area. In practice, we need to recognize the key roles that Guangzhou, Hong Kong, Macao, and other key cities played in the tourism-based economy, and focus on the transformation of the population, capital, and flow factors of other cities in relation to tourism development to strengthen the tourism foundations in this emerging region. Tourism can also result in ecological, economic, and environmental costs, and thus it is also necessary to focus on whether the policy of subsidizing tourism has a positive overall impact on the economic growth of the Greater Bay Area and its surrounding cities. How to maintain a positive relationship between economic growth and tourism should also be the focus of further research.