Although island tourism is vital to the economy of developing countries, many islands with great potential for tourism development do not plan for it adequately. The objective of this paper is to establish an island tourism value mining and promotion model from the tourist perspective by selecting the status value indicators of basic conditions, vacation tourism resources, and sightseeing tourism resources, as well as the promotion indicators of five types of recreational fisheries, including beach activities, recreational fishing, marine sports, rock climbing, and sightseeing platforms. Then, we evaluate the whole island and develop suitable areas by using an analytic hierarchy process. This study took Tianheng Island as an example and divided the study area into grids and land use types. The results indicate that the basic conditions and tourism resources of Tianheng Island are in a general level, and the vacation tourism resources are in high quality, while there is further room to improve them. We identified that the island has four areas which are suitable for scenic development, two sandy beaches, two recreation fishing areas, one marine sports area, and one island rock climbing area. Our findings are consistent with the actual situation in Tianheng Island, demonstrating that the model is practical and can provide an essential reference for the scientific protection and utilization of island tourism resources.