Abstract: The year of 2024 is the 65th year for Zhuhai city to supply water to Macao city, and also the 20th year for the Ministry of Water Resources to implement the emergency water regulation of the Pearl River with saltwater suppressing and freshwater replenishment in dry season. Based on the local "first line of defense", Zhuhai city has taken measures such as improving the raw water system, improving water quality, and optimizing scheduling, fully utilizing the emergency water regulation with a total length of more than 1 300 km to maximize the storage of freshwater resources in Zhuhai before they flow into the sea. Solving the problem of drinking salty water during the dry season in Zhuhai and Macao has enabled the "thousand mile water diversion" to maximize social and economic benefits, successfully ensuring the safety of water supply in Zhuhai and Macao cities. Thus provides successful case studies for regions similar to those affected by the salty tide.