Seriously poor water resources in China, per capita only 1/4 of the world average. In recent years, the rapid development of the iron and steel industry has vigorously promoted economic construction. However, a large amount of waste water is discharged during the steel production. The direct discharge of these waste water causes serious pollution to water resources and aggravates the water shortage. Therefore, increasing the recycling rate of water, reducing the consumption of new water, and realizing the recycling of waste water are not only important means for the sustainable development of the steel industry, but also a great event for protecting the environment, benefiting the nation and benefiting the people and the benefit of future generations.