On the basis of the Endogenous Growth Theory and in order to explore the endogenous powers of the tourism cooperation in the Greater Mekong Subregion(GMS)Economic Belt under the framework of the Belt and Road Initiative, this paper builds an endogenous power model consisting of three factors:acquiring new knowledge;stimulating the application of new knowledge in production and providing the resources of new knowledge application.Through a detailed analysis of the six specific components in the three factors, namely self-innovation ability, integration of tourism resources, policy support of the Belt and Road Initiative, GMS marketing integration, GMS culture integration and tour personnel training, the paper probes into the relationship between the components and the factors and studies the endogenous powers of the tourism cooperation in the GMS Economic Belt, so as to provide relevant ideas for the further development and inject new vitality into the regional tourism cooperation.