The invention discloses a special polyelement microorganism fertilizer for preventing potato soft rot and a preparation method of the special polyelement microorganism fertilizer. The special polyelement microorganism fertilizer comprises components of raw materials in parts by weight as follows: 0.4-0.6 part of bacillus polymyxa, 0.2-0.4 part of a fertilizer leavening agent, 90-110 parts of an organic fertilizer, 0.5-0.8 part of a plant growth regulator, 1-3 parts of an adhesion agent, 2-4 parts of an insecticide synergist, 30-60 parts of an inorganic fertilizer, Chinese herbal medicinal ingredients and the like. The prepared special polyelement microorganism fertilizer for preventing the potato soft rot can reduce the morbidity of the potato soft rot greatly and reduce bacterial and fungal diseases of leaves of a plant obviously, the plant can grow more vigorously, the yield of potatoes is increased greatly, the quality is improved, probiotics in the soil are also increased, and the soil condition is improved.