Sewage treatment agent and preparation method thereof

The invention discloses a sewage treatment agent and a preparation method thereof. The sewage treatment agent is prepared from raw materials in parts by mass as follows: 75-88 parts of diatom ooze, 12-36 parts of aluminum sulfate, 10-55 parts of oxalic acid, 15-25 parts of sodium silicate, 36-78 parts of sodium chloride, 20-35 parts of polyacrylamide, 19-22 parts of lime, 30-45 parts of alums, 25-45 parts of limestone, 25-45 parts of citric acid, 15-25 parts of sodium phosphate, 30-50 parts of persulfate, 15-25 parts of fly ash, 13-15 parts of lipase and the balance of deionized water. The sewage treatment agent is high in reaction speed, and no toxic or harmful gas is produced in the process; a product obtained after the reaction is stable and cannot be decomposed into toxic substances; the sewage treatment agent is efficient, non-toxic and safe to a human body before and after the reaction and doesn't corrode equipment; the use method is simple, the technological procedures are not modified, and equipment a