Cyclic production method of glyphosate

The invention relates to a cyclic production method of glyphosate, belonging to the technical field of pesticide production techniques. The production method comprises steps as follows: the raw material dimethyl phosphite is subjected to an alkyl ester method to obtain glyphosate and a glyphosate mother solution; the glyphosate mother solution is treated to obtain a secondary alkali mother solution; the secondary alkali mother solution is subjected to catalytic preoxidation, high-temperature high-pressure air electrocatalytic degradation and liquid membrane extraction to obtain a liquid membrane concentrated solution and a saliferous liquid membrane diluted solution; the liquid membrane concentrated solution is subjected to active carbon decoloration, concentration by evaporation, and high temperature polymerization to obtain sodium tripolyphosphate; the saliferous liquid membrane diluted solution is filtered by a nanofiltration membrane to obtain a membrane concentrated solution and a membrane diluted solution; the membrane concentrated solution returns to the catalytic preoxidation step to be recovered; the membrane diluted solution enters an MVR (mechanical vapor recompression) system to be subjected to concentration by evaporation, thereby obtaining sodium chloride crystal, distilled water and a mother solution; and the sodium chloride crystal, distilled water and mother solution are respectively utilized. The invention lowers the production cost, enhances the utilization ratio of the product, reduces the discharge of waste liquor in the glyphosate production procedure, is environment-friendly, and has obvious comprehensive economic benefit and social benefit.