An externally arranged
ultrahigh frequency partial discharge detection sensor comprises a
metal shielding outer shell, a
microstrip antenna and a
coaxial cable connector. The
metal shielding outer shell is a box body with an opening at the bottom, and the lower bottom edge of the long side wall is arc-shaped. The
microstrip antenna is arranged in the
metal shielding outer shell and is a rectangular paster antenna. Long edges of a conductor paster are respectively provided with an inward concave arc notch, arc notches are symmetrically arranged using a geometric center of the conductor paster as a symcenter, the
microstrip antenna is arranged in the metal shielding outer shell through a
dielectric substrate, and an earth plate of the
microstrip antenna is a metal shielding outer shell. An
integrated circuit board is arranged in the metal shielding outer shell. A
low noise amplifying circuit connected with the
microstrip antenna, a
detector circuit, an amplifying circuit which outputs signals through the
coaxial cable connector, and a power supply circuit are arranged on the
integrated circuit board. The externally arranged
ultrahigh frequency partial discharge detection sensor integrates the
microstrip antenna, the
integrated circuit board and the shielding outer shell, and is high in sensitivity, small in
signal distortion, good in
signal-to-
noise ratio characteristic, and capable of keeping characteristic information of
partial discharge signals to the maximum limit.