The Dunhuang Crescent Spring (Crescent Moon Spring, Yueya Spring, Crescent Lake) was formed in the Holocene of the Quaternary Period, about 12 ka ago. Because the spring lake is surrounded by the Mingsha Mountain, it looks like a crescent moon and has the characteristics of freshwater spring lake with the sand and water symbiosis, which has become an important geological heritage in the world. Based on the comprehensive analysis of the dynamic changes of water level in Crescent Springin in the last 100 years, it is considered that the comprehensive reasons for the dynamic change of water level in Crescent Spring can be attributed to climate and human factors. From 1960, agricultural well irrigation and the construction of the Danghe Reservoir and canal system led to the imbalance of groundwater recharge and discharge. By 2001, the water level of Crescent Spring had decreased by 9.98 m, with an average annual decrease of 0.24 m. The decline of regional groundwater level was the main reason for the decline of water level in Crescent Spring, and the increase of temperature and evaporation is the secondary reason for the dynamic change of water level in Crescent Spring. Through the artificial water supplement project of Crescent Spring, the water level has risen by 1.58 m from 2018 to 2019, and the water area of the lake has gradually expanded from 9472.59 m2 to 13334.75 m2. The beautiful appearance of Crescent Spring in the minds of the ancients has displayed again.