The invention discloses a distribution transformer three-phase current dynamic balancing apparatus and a work method thereof, relates to a middle-low voltage current balancing apparatus, and especially relates to a three-phase current dynamic balancing apparatus. The apparatus automatically balances a low-voltage power supply network, and is high in expandability, high in reliability and high in dynamic compensation precision. The apparatus comprises module units, a current acquisition unit, a remote communication unit and a man-machine interaction unit. The module units are connected in parallel with power network common connection points. Each module unit comprises an LCL filter, an inverter, a driving circuit and a central controller, wherein the central controller, the driving circuit, the inverter and the LCL filter are successively connected. Load conditions are monitored in real time and comprehensively reflected in real time, current conditions are timely and accurately fed back to the central controllers, and the central controllers can dynamically and accurately adjust three-phase load currents in real time so that the accuracy of dynamic current adjustment is improved; and a commissioning module is flexibly added and reduced, the product power consumption is reduced, and energy is saved.