The invention discloses an application of an OsAKT1 (Oryza sativa L. Arabidopsis K<+> transporter 1) protein in cultivating a low-potassium adversity stress-resistant plant. The invention provides a method for cultivating the low-potassium adversity stress-resistant plant. The method comprises the following steps: the coding gene of the OsAKT1 protein is transferred into a target plant so as to obtain a transgenic plant with increased low-potassium adversity stress resistant capability; the OsAKT1 protein is obtained from paddy (Oryza sativa) and is the protein of (a) or (b) as follows: (a) the OsAKT1 protein is the protein which consists of an amino acid sequence which is shown in a sequence 1 in a sequence table; and (b) the OsAKT1 protein is the protein which is obtained in the way that the amino acid sequence in the sequence 1 is replaced and/or deleted and/or added with one or more amino acid residues and is derived with the sequence 1 which is related to the low-potassium adversity stress resistance of the plant. The OsAKT1 protein can be used for improving the low-potassium resistant capability of the plants and provides guarantee for cultivating new paddy products which are suitable for potassium deficient soil.