Taking the water supply network of a region in Tianjin as an example,the EPANET software was used to do hydraulic calculation,the disadvantages of the present water supply network were specified. In order to ensure the security, the paper designed the renovation plan of network on the basis of actual survey, and selected some key nodes as the basis of comparison and analysis. According to the final result of hydraulic calculation, the paper proved the rationality of the network design and can provide scientific basis for actual project.