A power drive circuit includes a power conversion module, a plurality of gate drivers, a waveform processing unit, a control unit, a weighting unit, and a comparator. Each gate driver includes a drive resistance setting value. The waveform processing unit outputs a current absolute value waveform of an AC power. The weighting unit generates a trigger voltage. When the comparator determines that the current absolute value waveform is greater than the trigger voltage, the comparator outputs a slew rate control signal to each of the gate drivers. When the gate driver receives the slew rate control signal, each of the gate drivers decreases the drive resistance setting value of the gate driver.