Bushing internal fault judgment method for transformer partial discharge test

The invention belongs to the technical field of transformer test, and relates to a bushing internal fault judgment method for a transformer partial discharge test, which comprises the following steps of: performing square wave correction before the partial discharge test; a fault terminal with a partial discharge signal is connected in parallel with a load capacitor, the tail end of the load capacitor is connected with a partial discharge measurement impedance Zm, and square wave correction is carried out to enable a partial discharge tester channel for measuring the partial discharge measurement impedance Zm and a partial discharge tester channel for measuring the fault terminal to display the same discharge capacity value. Then applying voltage to the test transformer to carry out a partial discharge test; and if the discharge capacity value measured by the partial discharge tester channel for measuring the partial discharge measurement impedance Zm is less than half or more than half of the discharge capac