The coordinated development of the tourism industry is a powerful way to form a world-class city cluster in the Guangdong-Hong Kong-Macao Greater Bay Area. Tourism flow network analysis can understand the spatial pattern and cooperative and competitive relationship of tourism destinations in a region effectively，and further provide in-depth interpretation and effective suggestions for promoting regional tourism integration. Based on social media big data，this report constructs and analyzes the tourism flow network of the Guangdong-Hong Kong-Macao Greater Bay Area from the perspective of tourists’ destination selection behavior. The results show that：1） The mobile tourists in the Guangdong-Hong Kong-Macao Greater Bay Area have obvious demographic characteristics. 2） The spatial distribution of tourist destinations in the Guangdong-Hong Kong-Macao Greater Bay Area presents a form of competition and cooperation network of six subgroups. The six subgroups are Guangzhou subgroup，Zhuhai subgroup，Hong Kong and Macao subgroup. Shenzhen subgroup，and Huizhou-The Dongguan subgroup and the Foshan-Zhaoqing subgroup have obvious competition and cooperation within the subgroups，while it is relatively independent between subgroups. 3） There are obvious barriers to the flow of tourists between cities on the east and west banks of the Pearl River and between Hong Kong，Macao and Guangdong；the tourist flow network in Guangzhou has formed destination mobile network with the core of the Guangzhou Chimelong Tourist Resort and the Guangzhou Tower Scenic Area，Guangzhou Grandview Plaza Commercial and Tourist Area and Guangzhou Baiyun Mountain Scenic Area. During the process of flowing，tourists mostly choose post-modern tourism complex as the core tourist destination.