New technology for recycling metribuzin methylate mother liquor

The invention provides a technology for recycling metribuzin methylated mother liquor. The technology uses bromomethane as methylating agent to react with triazone under alkaline condition and obtain metribuzin; and methylated mother and bromine are recycled for cyclic utilization, thus achieving the aim of the reutilization of wastewater. The inorganic salt content and discharge amount of waste water in methylating working section can be effectively reduced, and the difficulty and cost of treating waste water are largely reduced. The invention has good environmental benefit, social benefit and economic benefit.