Tourism live broadcasting is a new marketing tool in the tourism industry. In this study, we used a mixed research method to investigate the underlying mechanism of tourism live broadcasting on customers’ purchase intention, which is at the heart of the new marketing research. We also applied flow theory to explore the role of flow experience in the relationship between live broadcasting and purchase intention. We proposed and tested four hypotheses: (1) Customer participation in tourism live broadcasting has a positive influence on purchase intention; (2) Different participation behaviors have different effects on tourists’ purchase intention toward tourism products; (3) Cooperation behavior has the most significant impact on customer purchase intention; (4) Flow experience mediates customer participation and purchase intention and completely mediates interpersonal interactions and purchase intention. The findings suggest that the marketing tool of tourism live broadcasting should focus on cultivating participants’ cooperative behavior and pay more attention to creating participants’ flow experience.