The invention discloses a process for purifying
glufosinate-
ammonium, which comprises: (1) adding
glufosinate-
ammonium hydrochloride into an
alcohol R1OH to perform an
esterification reaction, and after the reaction is accomplished, cooling, filtering, removing
solvent from filtrate and obtaining ester product of
glufosinate-
ammonium; (2) adding the ester product of glufosinate-ammonium, which isobtained by step (1), into water solution of
hydrochloric acid to perform a
hydrolysis reaction, and obtaining glufosinate-ammonium
hydrochloride by
post treatment; (3) adding the glufosinate-ammonium
hydrochloride obtained by the step (2) into an
alcohol R2OH, introducing
epoxy ethane and obtaining glufosinate-ammonium acid; and (4) adding the glufosinate-ammonium acid obtained by the step (3) into an
alcohol R3OH, introducing
ammonia gas, and obtaining glufosinate-ammonium after the reaction is finished. In the invention, the process for purifying glufosinate-ammonium comprises simple steps, the inorganic
salt content in the obtained glufosinate-ammonium is low, and the purity of the obtained glufosinate-ammonium is high; the process for separating glufosinate-ammonium hydrochloride from HCl by
epoxy ethane is more economic than the conventional process which adopts epoxypropane and
epoxy chloropropane; and the method is very safe and has a very bright industrialization prospect.