The invention discloses an equivalent height compensation measurement system and method of a local discharging ultrahigh-frequency sensor. The equivalent height compensation measurement system comprises a GTEM chamber, a radio-frequency signal source, a radio-frequency power amplifier, a coaxial connector, an electric field probe, an electric field measurement module, a monopole standard probe, ameasurement and control computer and a high-speed oscilloscope, wherein a test window is formed in a part above the GTEM chamber, and the monopole standard probe is used for transferring a known function. An electric field where a measurement position of the monopole standard probe is used as a reference, electric field values at different positions are measured by the electric field probes and are compared with an electric field reference to obtain corresponding compensation quantity, compensation calculation is performed on the electric field at a position where a measured ultrahigh-frequency sensor is located to obtain measured sensor compensation quantity, so that the influence of non-uniform electric field on equivalent height of the measured ultrahigh-frequency sensor caused by different test positions is reduced, and the equivalent height measurement accuracy of the ultrahigh-frequency sensor is further improved.