The invention discloses application of OsSGT1 protein and an encoding gene thereof to regulation and control over the salt resistance of a plant. The invention provides a method for cultivating a transgenic plant. The method comprises the step of introducing a gene for encoding the OsSGT1 protein into an initial plant to obtain the transgenic plant with reduced salt resistance. The OsSGT1 protein is (a1) or (a2) as follows: (a1) protein consisting of an amino acid sequence shown as a sequence 2 in a sequence table; and (a2) protein obtained by substituting and/or deleting and/or adding one or more amino acid residues on the basis of the amino acid sequence shown as the sequence 2, related to the salt resistance of the plant and derived from the sequence 2. The application provided by the invention has an important theoretical guiding significance and an important production application value in digging a salt-resistant gene of the plant, understanding the occurrence mechanism of salt stress, improving the salt resistance of the plant and cultivating a plant variety with strong salt resistance.