Production method of L-glufosinate

The invention discloses a production method of L-glufosinate. The method includes the steps that with 2-carbonyl-4-(hydroxyl methyl phosphoryl) butyric acid and salt thereof being a substrate, isolated transaminase or a cell catalysis substrate of in-vitro expression transaminase reacts with an amino donor under the condition that the amino donor exists, so that L-glufosinate is obtained, wherein the amino donor is alanine, and the amino acid sequence of transaminase is shown in SEQ ID NO.1-3. With 2-carbonyl-4-(hydroxyl methyl phosphoryl) butyric acid and salt thereof being the substrate and alanine being the amino donor, the transamination reaction occurs through the specific transaminase catalysis substrate, the substrate can be completely converted into L-glufosinate, and the conversion rate of raw materials is high and can reach 100%.