The invention discloses a method for preparing
magnesium L-pyroglutamate. The preparation process is as follows: a, preparing L-pyroglutamic acid by
dehydration, wherein L-
glutamic acid and deionized water are put into a reaction kettle, stirred, heated to 100 to 128 DEG C and kept at the temperature for 6 to 12 hours; b, separating and extracting the L-pyroglutamic acid, wherein after pyrogenation is finished, the reaction solution is cooled to
room temperature, deionized water is added to dilute the reaction solution, and the L-pyroglutamic acid and the non-pyrolyzed L-
glutamic acid are separated by a cation exchange resin column; c, preparing the
magnesium L-pyroglutamate, wherein the solution of the L-pyroglutamic acid obtained by the step b is stirred and heated and added with
magnesium carbonate or magnesium
oxide; and d, separating and extracting the magnesium L-pyroglutamate, wherein a sample is made after the reaction solution obtained by the step c is clear to test the pH value of the reaction solution, the pH value of the reaction solution is adjusted to 6.5 to 7.5, the reaction solution is concentrated till supersaturated solution is obtained, the supersaturated solution is stirred and cooled for
crystallization, the solution is subjected to vacuum
filtration and the crystals are subjected to
vacuum drying to obtain the magnesium L-pyroglutamate. The method is simple in operation, high production efficiency and low in cost and is suitable for industrial production.