The invention relates to a soybean conversion method which comprises the following steps: cotyledon and the first euphylla of germinated soybean seeds are removed, and naked meristem is obtained; the naked meristem is inoculated to a pretreatment culture medium containing cytokinin for pretreatment; meristem blocks after the pretreatment are infected by agrobacteria. According to the soybean conversion method, the soybean meristem blocks after the pretreatment are used as explant materials for the first time; the explant materials are subjected to high-concentration cytokinin treatment before agrobacterium infection so that the meristem of soybeans can be in an active state and exogenous genes can be inserted easily; meanwhile, the meristem is multiplied and enlarged, so that the infection process is more convenient to operate; in the process of agrobacterium infection, ultrasonic treatment is added, so that the efficiency of insertion of the exogenous genes in a plant genome is greatly improved, and the conversion rate of the soybeans can reach 10%; meanwhile, the conversion period is short, the number of chimera is small, and conversion cost is low.