Abstract: Sanya City is the only international tropical coastal tourism city in China, it is also an important node city of China’s 21st Century Maritime Silk Road, its ecological civilization construction caused extensive concern. According to the regional characteristics of Sanya City, the main problems in the ecological civilization construction are identified from the level of system, environment, and economy. It reveals that Sanya City had problems such as the ecological civilization system was still not perfect, the task of green economy development was arduous, the quality of local ecological environment was declining, and the level of tourism development was not high yet. On the basis of clarifying the regional functional orientation, the overall layout of the ecological civilization construction of the “mountain-sea-river-city (MSRC) model is put forward based on the concept of ecological priority and green development, and combining the unique geographical location and superior ecology resources of Sanya City. On this basis major tasks were proposed from six aspects, including institutional innovation, ecological remediation, green development, environmental improvement, concept propaganda, and characteristic construction, which comprehensively promoted the ecological civilization construction, and obtained an actual effect in Sanya City. It may lay a solid foundation for Sanya City’s goal of becoming a world-class coastal tourism city.