The invention discloses a high-voltage transformer resonance early warning method. The high-voltage transformer resonance early warning method comprises the steps that according to the obtained voltage output by a high-voltage transformer and the obtained current signals output by the high-voltage transformer, the value of a fundamental wave, the value of each harmonic wave and the value of each inter-harmonic are obtained through calculation; the value of one of the fundamental wave, each harmonic wave and each inter-harmonic is selected as an early warning comparison value; whether the early warning comparison value is larger than a preset value matched with the early warning comparison value is judged, and if yes, a warning signal is output to a first warning system through a wireless signal transceiver. In this way, even if a user is not on the work site of the high-voltage transformer, when the high-voltage transformer does not normally work, the user can obtain warning information from the first warning system.