Preparation method of high-performance cationic polyacrylamide flocculating agent

The invention mainly solves a technical problem of providing a preparation method of high-performance cationic polyacrylamide used in wastewater treatment. According to the invention, the temperature of an acrylamide water solution is increased to 45-50 DEG C; under an anaerobic condition, an initiator is added; the temperature of the system is maintained at 45-50 DEG C, and a reaction is carried out for at least 4h, such that a polymerization intermediate product is obtained; the polymerization intermediate product diluted and dissolved with water; amine and formaldehyde are added; a reaction is carried out for 2h under a temperature maintained at 45 DEG C; polybasic acid is added; when the system is in a gelatinous state, the temperature is maintained; and alkali is added, such that the pH value is regulated to above 8, until the system restores fluidity. According to the invention, through slowly dropping polybasic acid, a network structure formed by stretching polyacrylamide can be fixed, such that intramolecular crosslinking reaction can be reduced, and intermolecular crosslinking reaction can be increased. Also, the crosslinking degree is controlled through controlling the conditions such as formaldehyde dose and crosslinking reaction time, such that high-molecular-weight cationic polyacrylamide is obtained, and the prepared product has good flocculation effect.