Process for preparing trisodium phosphate from glyphosate mother liquid

The invention provides a process for directly preparing trisodium phosphate from glyphosate mother liquid in order to effectively recover phosphorus resources from the mother liquid for producing trisodium phosphate. The process is characterized by comprising the following steps: oxidizing the glyphosate mother liquid through catalytic air, oxidizing organic phosphine in the mother liquid into orthophosphate ions, adding sodium hydroxide or sodium carbonate into the mother liquid to adjust the pH value to be 9-10, cooling to be -5 DEG C to 8 DEG C while stirring, crystallizing, separating, washing, and drying to obtain trisodium phosphate. The process is simple and easy for industrialization applications, the obtained trisodium phosphate is wide in application range, difficulty in enabling the glyphosate mother liquid subjected to terminal treatment to reach the emission standard is lowered, and treated solid waste is reduced.