Method for preparing L-glufosinate-ammonium through double enzyme combination

The invention discloses a method for preparing L-glufosinate-ammonium through double enzyme combination, which comprises the following steps: by taking 2-acetamido 4-[hydroxyl (methyl) phosphonyl]-DL-butyric acid or salt thereof as a raw material, carrying out hydrolysis reaction on a system formed by the raw material, anhydrous cobalt chloride and water, L-acetyl amino acid hydrolase and acetyl amino acid racemase under a certain pH condition to obtain an L-glufosinate-ammonium aqueous solution; treating an L-glufosinate-ammonium aqueous solution through a micro-filtration membrane to remove enzyme, treating the L-glufosinate-ammonium aqueous solution through a nano-filtration membrane to remove salt, adding ammonia water to adjust the pH value to 4-7, and sequentially concentrating and crystallizing with methanol to obtain the L-glufosinate-ammonium. according to the method, the two enzymes are commercialized, the commercialized codes of the L-acetyl amino acid hydrolase and the commercialized codes of the