The invention discloses a selenium-enriched microorganism preparation prepared from fermentation of a mixed bacterium liquid. The selenium-enriched microorganism preparation consists of the following raw materials: sodium selenite, complex trace elements, monopotassium phosphate, urine, peptone powder, NaCl, NaOH, NaNO3, NaCl, NH4Cl, K2HPO4, a beef extract, glucose, starch, calcium carbonate, amino acid, potassium nitride, ferrous sulfate, magnesium sulfate, trisodium citrate, a biochemical enzyme and a mixed bacterium liquid; and the mixed bacterium liquid is a mixed liquid of the bacterium liquid of bacillus amyloliquefaciens, the bacterium liquid of bacillus subtilis, the bacterium liquid of bacillus licheniformis, the bacterium liquid of bacillus thuringiensis and the bacterium liquid of bacillus mucilaginosus. The mixed bacterium liquid applicable to the selenium-enriched microorganism preparation disclosed by the invention is conducive to microorganisms in soil, and can be used for increasing the quantity of the microorganisms in the soil and enhancing the activity of the microorganisms in the soil. Due to vital activity and metabolite, the strain is an agricultural product which can cause special fertilizer effect, growth regulating effect, effect of prevention and control of plant diseases and pests, soil bioremediation and the like to crops.