The invention discloses a device and a method for electrified monitoring of transformer winding deformation. The device comprises an excitation source, an excitation signal injection sensor, response signal measuring sensors and a main controller, wherein the excitation source is used for receiving a sweep frequency sinusoidal voltage signal output by the main controller, and outputting the sweep frequency sinusoidal voltage signal to the excitation signal injection sensor after carrying out power amplification; the excitation signal injection sensor is used for generating induced potential on a transformer winding in a magnetic field coupling manner according to the sweep frequency sinusoidal voltage signal; the response signal measuring sensors are used for measuring sweep frequency response current signals generated by means of the induced potential on two ends of the transformer winding, and outputting the sweep frequency response current signals to the main controller; and the main controller is used for acquiring a frequency response curve of the transformer winding according to the sweep frequency sinusoidal voltage signal and the sweep frequency response current signals. According to the method and the device, the injection of the excitation signal and the measurement of the response signals do not require direct connection with the transformer winding, and the real-time detection of the winding deformation condition of an online operating transformer is realized.