New high-efficiency flocculation water treatment agent. Polymeric ferric sulfate is used in the treatment of environmental protection and industrial waste water. The method of use is basically the same as that of water plants. It is very effective for the treatment of raw water with high chroma, high COD and BOD, supplemented by additives. It is a new and efficient flocculant. It is mainly used for the purification of drinking water and industrial water. It can also purify various industrial wastewater and urban sewage (such as food, leather, mining, metallurgy, printing and dyeing, papermaking, petroleum and other wastewater).