The present invention provides a method for creating a photo-thermo-sensitive sterile line by using NPU gene mutation, and applications of the photo-thermo-sensitive sterile line. According to the present invention, the photo-thermo-sensitive sterile line is achieved by inhibiting the expression of NPU protein associated with plant pollen development; and the sterile line for a variety of specific plants is firstly found, and by regulating the expression or the activity of the NPU protein associated with pollen development, the fertility of the plant is regulated so as to achieve the controlled conversion between sterility and fertility. The invention further discloses applications of the plant sterile line in agricultural breeding and other fields, wherein the breeding method of the plant sterile line is substantially simplified.