The invention belongs to the field of biotechnology and discloses an agrobacterium-mediated soybean rapid genetic transformation method. The method comprises the steps of obtaining an exophyte, carrying out genetic transformation and co-culture, shoot elongation and screening culture and rooting culture. The method is characterized in that: an overall cotyledonary node is taken as the exophyte, and agrobacterium engineering bacteria fluid carrying target genes is dipped to infest the overall cotyledonary node by using a sterile cotton ball so as to carry out the genetic transformation. According to the agrobacterium-mediated soybean rapid genetic transformation method, the traditional single cotyledonary-node method for the exophyte is transformed into an overall cotyledonary-node method, and thus, the transformation period is shorter; and compared with the traditional single cotyledonary-node method, under the condition that the transformation ratio is not lowered, the period for obtaining transgenic plants can be shortened to 5-6 weeks from over 8 weeks spent when the single cotyledonary-node method is adopted , so that the process for soybean genetic transformation is improved.