In the new era, promoting high-quality development has become the theme of China's economic and social development. Based on the high-quality development connotation of national water park, this paper constructs an evaluation index system of high-quality development of national water park, including 23 main contents and 52 evaluation indexes, from the six aspects of distinctive characteristics of water conservancy, excellent ecological environment, rich cultural atmosphere, strong development momentum, safe and efficient management, and significant comprehensive benefits. Using the Delphi method, the evaluation results are divided into three grades, thus forming a high-quality development evaluation system for national water park. The evaluation system has been preliminarily applied to the collection and selection of 30 typical cases of high-quality development of national water park, and has achieved good application results.