Abstract: Polyferric chloride sulfate （PFCS） is a new-type high-performance inorganic macromolecular water treatment agent.Its main preparation methods include chlorate oxidation method and chlorine oxidation method,namely ferrous sulfate solution react with sodium chlorate or liquid chlorine at a certain temperature and acidity to generate a series of  PFCS solution with different polymerization degrees.Temperature,acidity,and oxidants can affect polymerization degree of the products and effect will differ greatly when they were used as water treatment agents.Compared with chlorine oxidation method,the other one is dominant in both terms of cost and environment protection,and it represents the industrial production method for PFCS.