Copolymerization manufacturing method of polyacrylamide with ultralow content of residual monomers

The invention discloses a copolymerization manufacturing method of polyacrylamide with ultralow content of residual monomers. The copolymerization manufacturing method includes the following steps of (1), adding 5 cubic meters of deionized water into a polymerizer, adding 2000-4000kg of acrylamide-acrylic acid mixtures, controlling the temperature of the polymerizer at 0-15 DEG C, adding 55-2110kg of sodium hydroxide into the liquor, regulating pH of the liquor at 6-9, controlling the temperature of the polymerizer at 3-10 DEG C, adding assistants, performing mixing and stirring to obtain reaction liquid, and transferring the reaction liquid into the polymerizer, wherein acrylamide accounts for 5-95% of the mixtures, and the balance is the acrylic acid; (2), injecting nitrogen into the polymerizer for 30 minutes, adding initiators into the polymerizer, continuing to inject the nitrogen until the reaction liquid becomes dense, closing the polymerizer, controlling the reaction time within 4-10 hours, and increa