The invention discloses a three-phase inverter least switching loss method based on dual-carrier and synthetic modulation wave. The method comprises the following steps: S1, superposing a zero-sequence component on a sine modulation wave to form the synthetic modulation wave in a modulation way; and step S2, superposing the synthetic modulation wave on the bipolar carrier to form a driving signalGa, a driving Gb and a driving signal Gc in the modulation way. Through the three-phase inverter least switching loss method based on the dual-carrier and the synthetic modulation wave, the defect that the traditional DPWM can realize the least switching loss only in the specific power factor range is avoided by adopting the bipolar carrier and the least switching loss PWM strategy based on the zero sequence component and the sine wave synthetic modulation wave, so that the switching loss can be further optimized when the power factor range is further reduced, thereby realizing the switching loss least discontinuous modulation strategy DPWM in the full power factor range.