The invention relates to a modularized multi-level three-phase voltage source converter and belongs to the field of electrical automation devices. The modularized multi-level three-phase voltage source converter comprises six current converting arms and six filter reactors. Three anode ends of three current converting arms of a first group serve as a direct current anode end of the converter after connected together, cathode ends of the three current converting arms of the first group are connected to one ends of three filter reactors of the first group respectively, and the other ends of three filter reactors of the first group serve as three-phase alternating current phase wire ends of the converter respectively. Three cathode ends of three current converting arms of a second group serve as direct current cathode ends of the converter after connected together, anodes ends of the three current converting arms of the second group are connected to one ends of three filter reactors of the second group respectively, and the other ends of three filter reactors of the second group serve as three-phase alternating current phase wire ends of the converter respectively. According to the modularized multi-level three-phase voltage source converter, multi-level high-voltage current transforming application, back-to-back connection of direct current sides of two converters and protection of direct current sides in case of short circuit can be achieved.