Abstract: Macao and Zhuhai are connected by the same river. The high-quality and stable fresh water supply of Zhuhai is crucial to the people's welfare and the lifeline of the cities of Macao and Zhuhai. However, the water intake of Zhuhai is constantly threatened by salt tide. Under the influence of complex factors such as climate change and estuary morphology change, the duration and scope of salt tides becomes longer and wider, and the situation of salt tide is becoming more and more serious. Over the years, under the professional guidance and precise reservoir regulation of the Pearl River Water Conservancy Commission of the Ministry of Water Resources and the Guangdong Provincial Water Department, and the high attention of the Zhuhai Municipal government, Zhuhai has based on the actual water supply in the salty period, tapped the potential to make up for the shortcomings, strengthened the construction of local fresh water storage capacity, planned in advance, scientific scheduling, implemented management methods such as protection of drinking water sources and prevention and control of oil pollution. At the same time, it has strengthened exchanges with Macao to provide a solid guarantee for water supply in the dry season of Macao. It may provide reference for salt tide response and water supply security in other regions.