Polymerized ferrous sulfate is a kind of inorganic polymer coagulant with superior performance. Its morphology is light yellow amorphous powder solid, which is extremely soluble in water. 10% (mass) of the water solution is a red-brown transparent solution with hygroscopicity. Polymerized ferrous sulfate is widely used in purification treatment of drinking water, industrial water, various industrial wastewater, urban sewage, sludge dewatering, etc.