Accompanying with the development of computer technology and network technology, enterprises have built their Intranet. This paper is dealing with how to construct the plant management information system based on Intranet, and lays emphasis on the subsystem division using structural system analysis and design method. Accompanying with the development of computer technology and network technology, enterprises have built their Intranet. This paper is dealing with how to construct the plant management information system based on Intranet, and lays emphasis on the subsystem division using structural system analysis and design method.