The invention discloses a preparation method of a glucose-iron-
zinc double complex, which comprises the following steps: dissolving glucose in water, adding ferrite under a stirring condition, uniformly stirring, adjusting the pH value to 7.5-8.5 by using a
sodium hydroxide aqueous solution, and stirring and reacting at 70-90 DEG C for 1-2 hours to obtain a reaction solution A; adding
zinc salt into the reaction liquid A, uniformly stirring, adjusting the pH value to 8.0-9.0 by using a
sodium hydroxide aqueous solution, and stirring and reacting at 70-90 DEG C for 1-2 hours to obtain a reaction liquid B; and carrying out
microwave treatment on the reaction liquid B, adding an
ethanol water solution under a stirring condition, standing at normal temperature, separating out precipitate, and carrying out
vacuum drying on the precipitate to obtain the glucose-iron-
zinc double complex. Glucose sequentially reacts with
ferrous salt and zinc salt,
metal ions are complexed, the glucose-iron-zinc double complex is prepared, and the glucose-iron-zinc double complex is good in stability, good in
solubility and easy to absorb, is added into
animal feed, is high in
bioavailability and can promote growth and development of animals, reduce the
diarrhea rate and improve the health level of the animals.