Balancing the relationship between tourism economy and ecosystem is an important prerequisite for achieving sustainable economic development. Taking Changhai County as an example, this paper constructs a tourism economy and ecological environment evaluation index system to calculate their comprehensive indexes, analyzes the time series evolution characteristics of their coupling coordination degree by using the coupling coordination model, and judges their dynamic response relationship by using the vector auto-regressive（VAR）model. The research shows that from 2010 to 2018, the tourism economy and ecological environment of Changhai County were promoted synchronously, and their comprehensive index and coupling coordination degree increased with time, showing a trend of optimal development;the response of the tourism economy to its own shocks turned from positive to negative after 2011;and the response of the ecological environment to the tourism economic shocks turned from negative to positive, the response relationship between the tourism economy and the ecological environment of Changhai County finally became stable after 2013. The tourism economy and the ecological environment are mutually causal. In the short term, the tourism economy is greatly affected by itself. In the long term, the tourism economy is affected by itself and the ecological environment, while the ecological environment is continuously affected by both the tourism economy and itself. The impact of the tourism economy on the ecological environment is increasing year by year. It is suggested that Changhai County adhere to ecological protection, timely adjust relevant policies, promote high-quality development of tourism industry, promote scientific transformation of island economy, and maintain the coordination and balance between tourism economy and ecological environment. [ABSTRACT FROM AUTHOR]