Based on the method of comprehensive simulation, this paper built the early warning evaluation index system of tourism economy composed of four aspects and 26 indicators including the scale, structure, benefits and carrying capacity. Taking China’s coastal areas as the research unit, the year of 2000 to 2011 as the research time, this paper comparatively analyzed the regional differences of the tourism economic early warning composite index from the space-time point. The results showed that the warning composite index of tourism economy in coastal areas experienced the moderate warning area (2000-2008) and the serious warning area (2009-2011). Especially, the tourism economy scale entered the serious area from 2007 year on, indicating that the scale quantity type of development would inhibit the sustainable development of tourism economy. From the spatial point, the overall tourism economic development in China’s 11 coastal areas showed normal development trend, and belonged to the moderate warning area in addition to Shanghai. The coastal areas should formulate reasonable development strategy according to its own tourism economic development speed and warning condition, and focus on the quality of the tourism economic development, in order to promote the sustainable development of the tourism economy.