Tourism has rapidly developed into one of the world’s largest industries, and represents a new growth point for stimulating a region’s economic and social development. Therefore, a clear understanding of the interactive relationship between the tourism industry, the economy and the environment, as well as the potential mechanisms involved, can play an important role in improving the coordination between these three elements and forming a sustainable development policy. By utilizing quantitative analysis methods and models, this study uses Qingyang City, Gansu Province, as a case study, and tests the relationship between the development of the tourism industry, the economy and the environment. This study makes a number of important conclusions: (1) a mutually promoting relationship does not exist between the development of the tourism industry and economic growth; instead, a unidirectional relationship is found between the two elements. Similarly, a mutually promoting relationship does not exist between the development of the tourism industry and environmental quality; rather, a unidirectional relationship is found between the two elements. (2) The “curse effect” on economic growth imposed by the development of the tourism industry is found to exist. The development of the tourism industry not only exerts a direct negative influence on economic growth, but also adversely affects it in an indirect way through its influence over some transmission factors. Additionally, the curse effect on the environment imposed by the development of the tourism industry is also found to exist. The development of the tourism industry not only imposes a direct negative influence on the environment, but also adversely affects it in an indirect way through its influence over some transmission factors. (3) During the process of regional development, the relationship between the tourism industry, the economy and the environment needs to be correctly addressed. Through effective policies, it should be possible to realize the coordination of and sustainable development between the tourism industry, the economy and the environment.