Abstract: In this paper, the development trend and the general significance of the supervisory control system is analyzed, and also a design project of water supply's supervisory control and data acquistion system based on Web is introduced. The Web database adopts ASP technology to realize, and the long distance intelligent terminal uses MCU system. The user can supervise and control the water supply's equipments though the browser. The design has met with success in the system of railway water supply's supervisory control. Though the combination between control network and Internet, the corporation can achieve its automation with c ontrol, management, information and network together.