The invention provides a calibration device and method of an ultra-high frequency partial discharge sensor. The calibration device and method are matched with an ultra-high frequency partial discharge sensor to be calibrated. The calibration device includes a signal generator for providing ultra-high frequency signals, a signal receiver for receiving the ultra-high frequency signals, impedance transition sections for eliminating ultra-high frequency signal refraction and reflection, a coaxial transmission line used for generating TEM waves when the ultra-high frequency signals are transmitted, a matching impedor and an oscilloscope for displaying the frequency and amplitude of the TEM waves; two impedance transition sections exist and are circular cone-shaped; the top parts of the circular cone-shaped structures of the two impedance transition sections are provided with the matching impedor and the signal receiver connected with the signal generator respectively; the coaxial transmission line is arranged between the bottoms of the circular cone-shaped structures of the two impedance transition sections; the coaxial transmission line is a hollow circular cylinder; and the inner wall of the coaxial transmission line is provided with the ultra-high frequency partial discharge sensor to be calibrated which is connected with the oscilloscope. With the calibration device provided by the embodiment of the invention adopted, the sensitivity and bandwidth of the ultra-high frequency partial discharge sensor can be calibrated more accurately, and workload can be reduced.