Mixed chemical flocculation water purifying agent and preparation method thereof

The invention discloses a mixed chemical flocculation water purifying agent and a preparation method thereof, and the mixed chemical flocculation water purifying agent comprises the following components by weight: 2-4% of an ethylenediamine-dimethylaminopropane-epichlorohydrin copolymer; 5 to 6% of poly dimethyl diene propylene; 0-1% of a polyamine cationic polymer; 2-3% of a polyethyleneimine cationic polymer; 0.1% of a polyaluminum chloride solution with a concentration of 10%; and the balance of water. According to the mixed chemical flocculation water purifying agent, the power plant desulfurization wastewater needing to be treated is added at a time, cooperation of other agents is not needed, the mixed chemical flocculation water purifying agent is more optimized and simplified compared with an original treatment method, labor intensity can be relieved, dosing equipment and processes of existing enterprises are greatly simplified, a work site can be cleaner and more environmentally friendly, and the trea