The invention discloses a special disinsection and sterilization polyelement microorganism fertilizer for preventing cabbage downy mildew. The special disinsection and sterilization polyelement microorganism fertilizer comprises components of raw materials in parts by weight as follows: 3-5 parts of bacillus subtilis, 1-4 parts of trichoderma reesei, 4-8 parts of a fertilizer leavening agent, 1000-1100 parts of an organic fertilizer, 350-500 parts of an inorganic fertilizer, 65-85 parts of a trace element, 5-7 parts of a plant growth regulator, 25-35 parts of an adhesion agent, Chinese herbal medicinal ingredients and the like. The special disinsection and sterilization polyelement microorganism fertilizer for preventing the cabbage downy mildew can reduce the morbidity of the cabbage downy mildew greatly, and reduce bacterial and fungal diseases of leaves of a plant obviously, the plant can grow more vigorously, the yield of cabbages isincreased greatly, the quality is improved, and probiotics in the soil are also increased.