In this paper, GANTT chart and network chart are analysized and compared. The concept of energy network is introduced and the physics model of power nodes energy network is established in iron and steel plant.The residual heat and energy recovery utilization of integrated iron and steel works has been analyzed on the basis of the status of its energy utilization. A few relatively mature technical schemes in electric power generation with waste heat as well as technical have been suggested and power generation principles and characteristics have been elaborated. Discusses the benefits of saving energy from the data of economics.