Water slag is one of the main wastes discharged from industrial production. It is formed by rapidly cooling the hot-melt blast furnace slag in water. There are mainly two ways of slag pool water quenching and furnace water quenching. Due to the water slag is formed in the process of rapid cooling and has potential hydraulic cementitious properties, the hardness of water slag is very high and it is not easy to treat. At the same time, however, it also has a high use value. Water slag is an ideal raw material of cement and concrete. It can also produce new building materials such as slag Portland cement, gypsum slag cement, lime slag cement, slag brick and slag concrete.