The invention discloses green and environment friendly slow-release fertilizer synergist used for corn. The fertilizer synergist comprises, by weight, 1-2 parts of borax, 14-16 parts of potassium humate, 1-2 parts of aluminium potassium sulfate, 6-8 parts of sea-foam stone powder, 23-25 parts of peanut shell coarse powder, 27-29 parts of furfural residue, 8-10 parts of charcoal, 2-4 parts of slow-release microbial zones, 4-5 parts of slow-release microelement chelation layers, 6-9 parts of slow-release sitallization powdered rock phosphate coating layers and a defined amount of water. According to the fertilizer synergist used for the corn, the release rate of effective constituents is consistent with that of fertilizer requirement laws of the corn, meanwhile, the content of absorbable nutrients in the soil is increased, the effective nutrient utilization rate of combined application fertilizer is improved, the randomness and blindness of fertilization are overcome, the waste of fertilizer is reduced, the production cost is reduced, and a path for developing green corn plantation industry and protecting ecological environment is provided.