The invention discloses a dead-zone error voltage compensation method of T-type three-level inverter based on MSOGI-FLL, by detecting the three-phase output current of the three-level inverter T, three-phase measurement current is obtained; The three-phase measurement current of three-phase stationary coordinate system is converted into two-phase measurement current of two-phase stationary coordinate system by CLARK conversion module. Via MSOGI-FLL module locks the measured current in two-phase stationary coordinate system and filters the harmonic and high frequency noise to obtain the fundamental current signal. The fundamental current signal of two-phase stationary coordinate system is converted into three-phase current signal containing accurate current polarity information by CLARK inverse transform module. Three-phase current given signal, dead-time error voltage average and three-phase voltage modulation wave are input into modulation wave adjusting module at the same time, and voltage modulation wave after amplitude adjustment is obtained, and dead-time error voltage is compensated. The invention utilizes MSOGI-FLL module accurately detects the current polarity at the zero crossing point, and effectively improves the error voltage compensation accuracy of the T-type three-level inverter.