The present invention relates to a soybean improvement embryonic tip transformation method, which is a transformation method for embryonic tip with one cotyledon by using agrobacterium-mediated vacuum infiltration assisted exogenous gene transformation. The method comprises the following steps: obtaining a soybean explant having one cotyledon, and adopting agrobacterium vacuum infiltration assisted infection and co-culture to transform to obtain genetically modified soybeans, wherein the soybean explant is the embryonic tip obtained through sterile water soaking germination and removal of episperm, one cotyledon and ante-phyllome, and the infection method is vacuum infiltration assisted infection, wherein 0.05 MPa pressure is maintained for 5-8 min, and oscillation infection is performed for 1 h at a speed of 150 r/min under a dark environment of a temperature of 28 DEG C. The present invention provides a method for adopting the embryonic tip with one cotyledon as a receptor to create a soybean genetic transformation system, wherein a tissue culture stage is not required, a regeneration plant can be obtained in a short time, the method can be applicable for a base operation system of soybean gene engineering, and important theoretical and practical significances are provided for soybean quality improvement.