Water is the source of life and a precious resource given to us by nature. Water is inseparable from human daily production and life. Water resources play an irreplaceable key role in promoting social development and promoting a better life. However，with the rapid development of the economy，the water environment has deteriorated，and water pollution problems have emerged endlessly. Water quality monitoring is the first step in water environmental protection and governance. Only by fully grasping the raw water quality information can we find and solve pollution problems faster and better，and maintain the sustainable development of water resources，especially drinking water，which is closely related to human health And its water quality safety is even more important. However，there are currently problems such as water pollution in water sources，old pipe networks，and frequent water quality incidents. Water supply safety is threatened by various kinds. Water quality monitoring is an important means to ensure water safety. Based on the analysis of water quality monitoring，industry policies，and water supply status，the author explores how water quality monitoring and water quality research can effectively and effectively ensure water supply security，and gives future development trends and recommendations for the Guangdong-Hong Kong-Macao Greater Bay. The district water supply security guarantee provides a reference.