The invention provides a processing method and a processing device for the power-down shutdown of a variable-frequency compressor. The method comprises the following steps of determining whether an oscillation waveform occurs in the waveform of the input current of the variable-frequency compressor or not when the voltage input of the commercial power is stopped; when it is determined that the oscillation waveform appears in the waveform of the input current of the variable-frequency compressor, determining whether the voltage value of a direct current bus is larger than a preset adjustment value or not; if yes, increasing the value range of a modulation coefficient; otherwise, adjusting the flux weakening control modulation rate, and increasing the overload frequency reduction rate. According to the scheme, the vibration of the variable-frequency compressor during the power-down shutdown process can be avoided.