The invention provides a
glufosinate purifying technology including the following steps: (1) adding
glufosinate hydrochloride to
alcohol R1OH, adding R2NH2 for ammoniation, adjusting the pH to 7.0-14.0, cooling and filtering, removing a
solvent from a filtrate to obtain
glufosinate ammonium salt and a small amount of organic impurities; (2) dissolving the
glufosinate ammonium salt obtained by the steps (1) in an appropriate amount of water, leading in CO2 for neutralizing to the pH of 2.0-5.0, adding a proper amount of
alcohol R3OH for
precipitation of glufosinate acid, centrifugally filtrating to obtain the glufosinate acid which contains a small amount of
ammonium hydrogen carbonate or organic amine carbonates; (3) heating for
drying a glufosinate acid filtering cake obtained by the step (2) for
decomposition and volatilization of the
ammonium hydrogen carbonate or organic amine carbonates to obtain high purity glufosinate acid. The glufosinate purifying technology is simple in steps, the obtained glufosinate is low in inorganic
salt content and high in purity, and compared with a traditional technology using
epoxy ethane and
epoxy propane, the purifying technology using
carbon dioxide for separation of glufosinate
hydrochloride and HCl is more economical, and high in safety, and has a higher industrialization prospect.