The invention discloses a selenium-enriched peanut cultivation nutrient solution. A preparation method of the selenium-enriched peanut cultivation nutrient solution comprises the following steps: (1) preparation of raw materials: preparing 100 parts of purified water, 0.6-1.0 parts of L-selenomethionine and 0.1-0.3 part of hydroxyethyl cellulose; and (2) mixing the raw materials in the step (1), grinding into thick liquid to obtain pulp, sterilizing, cooling to the temperature of 25 DEG C, inoculating matured bacillus subtilis liquid strain in the pulp according to the volume percent of 5-10%, placing in a fermenting tank, feeding sterile air in the fermenting tank, carrying out stirring fermentation, after fermentation is finished, rapidly heating to the temperature of 70 DEG C, maintaining for 0.5-1.0 hour, and inactivating to obtain the final product.