The control system of sluice gates in Changbei is mainly responsible for the flood control and drainage in the Changbei district of Nanchang city. Taking the Qianhu Electric Drainage Station as a case study, we present the structure of the control system which is based on industrial Ethernet and is in line with the criteria for choosing PLC (Programmable Logic Controller). The principle of local control program and some of the program examples are also stated according to the programming flowchart. What's more, we introduce the design method of the industrial Ethernet-based WinCC configuration software, and give examples of the control interfaces. In line with the requirements for developing "Digital Changbei", the system is well extensible. The combination of software and hardware ensures the response speed of the system. Since its operation, the system has been working reliably. It also reduces the perils and inaccuracy of human operation and lessens human labor. This system accomplishes its goals and wins high reputation among clients.