Multi-polymerization preparation method of flocculant

The invention relates to the field of water-soluble polymer chemical auxiliary agents, and particularly relates to a multi-polymerization preparation method of a flocculant. The flocculant is prepared from the following raw materials in parts by weight:120-200 parts of non-ionic monomer, 10-40 parts of anionic monomer, 80-170 parts of cationic monomer, 600-700 parts of deionized water, and 0.08-0.12 parts of initiator. The preparation process comprises the following steps of: adding the non-ionic monomer, the anionic monomer, the cationic monomer and deionized water to a reactor, introducing nitrogen to remove oxygen, adjusting the PH to 4-5, adding the initiator and polymerizing at 2-5 DEG C; and after reaction is finished, granulating the polymer, drying colloidal particles at 70-80 DEGC, and finally crushing the colloidal particles to obtain the product. The product has higher-density charged groups, stronger adsorption capturing capability to colloid and suspended particles in water, and high-salt, acid and base resistance; and compared with other flocculants, the flocculant has the characteristics of good broad spectrum property, good stability and good flocculation effect.