The invention provides a preparation method and application of
magnesium L-threonate, and belongs to the technical field of medicines. The preparation method comprises the following steps: dissolving L-
ascorbic acid in water, adding
magnesium hydroxide and alkaline
magnesium carbonate, stirring, dropwise adding
hydrogen peroxide, heating, stirring and reacting, filtering a product, purifying and concentrating by temperature-sensitive molecularly imprinted hydrogel while the product is hot, adding an
ethanol water solution into a concentrated solution, standing, crystallizing, filtering, washing and
drying to obtain the magnesium L-threonate. And cooling the temperature-sensitive molecularly imprinted hydrogel after adsorption to
room temperature, washing and repeatedly using the temperature-sensitive molecularly imprinted hydrogel. The magnesium L-threonate is simple in preparation method, high in purity and high in yield, meanwhile, the slow-release magnesium L-threonate is prepared, and the magnesium L-threonate is low in
toxicity, good in
biocompatibility, large in
drug loading capacity, low in economic cost and good in
drug effect and has wide application prospects in preparation of anti-depression drugs.