Abstract: Water network optimization is an important method to solve the water shortage and pollution problems of industrial parks and improve the ability of water saving and emission reduction of industrial production. In recent years, the attention on carbon emission has brought new opportunites and challenges to the water network optimization under the background of the goal of "carbon peak & carbon neutrality". A water network optimization model under low-carbon constraints considering the constraints of water balance, supply and demand balance, available water supply, non-negative numbers, and carbon-water relation index was constructed and solved using genetic algorithms and ideal point methods. The objectives of the model were to minimize freshwater consumption, carbon emissions, and water treatment costs. The results showed that the water network optimization scheme under low-carbon constraints was expected to reduce fresh water consumption by 51% and carbon emissions by 65% in the Yancheng industrial park, focused on the electronic information industry. Measures for water saving and carbon reduction of the water network in industrial parks include multi-stage treatment-multi-stage reuse, optimization of process flow, optimization of pump operation, and chemical dosing. This research can provide support for the study of water saving, pollution, and carbon reduction in urban industrial parks.