The invention belongs to the technical field of power electronics, and particularly relates to a dead-zone-free space vector pulse width modulation method for a three-level inverter. The method comprises the following steps: in each phase, when the current is a forward current, switching off a third switching tube in advance of td time within the time that t belongs to [t1, t2], and normally connecting a first switching tube, wherein td = t2-t1; when the current is negative current, switching off the first switching tube in advance of td time within the time of t that belongs to [t3, t4], normally connecting the second switching tube, wherein td = t4-t3, and the traditional three-level space vector pulse width modulation method is still followed in other time periods; according to the principle of volt-second balance, obtaining the modulation time, comparing the modulation time with a triangular carrier wave to generate a three-phase PWM driving signal, and eliminating a dead zone effect of space vector pulse width modulation through the three-phase PWM driving signal. According to the method, the multi-modulation time is compared with triangular waves, driving signals of the switching tubes are led out through the adding of the simple logic operation according to the direction of three-phase current, and the traditional dead zone setting is cancelled.