The invention discloses a mycorrhizal inoculant and a preparation method thereof, and belongs to the technical field of mycorrhizal inoculants. The preparation method of the mycorrhizal inoculant comprises the following steps: S1, strain propagation: uniformly mixing
distilled water,
bran,
ammonium molybdate,
sodium tripolyphosphate and glucose, sterilizing, inoculating strains and sudangrass seeds, performing sterile culture in a
plant tissue culture bottle for 3-5 weeks, and taking roots and a culture medium as propagation strains; S2, preparing: adding the propagation strains into a
solid culture medium, uniformly mixing,
sowing the sudangrass seeds, uniformly stirring, after
seedling emergence, continuously culturing for 2-3 months,
cutting off the overground part of the sudangrass,
cutting into root segments, uniformly mixing with a culture medium, and
drying and crushing a preparation, so as to obtain the mycorrhizal inoculant. The
mycorrhiza fungicide can promote plants to absorb nutrients from unweathered mineral substances, meanwhile,
mycorrhiza generates various growth stimulants in the
metabolic process,
nutrient operation in the plants is adjusted, and then
crop growth is promoted.