The invention provides an electromagnetic type on-load voltage regulation system and method for a power distribution network. The system provided by the invention comprises a controller, a multi-geartransformer, a load, multiple contactors, multiple current-limiting resistors and multiple thyristor groups. The method provided by the invention utilizes the controller for controlling contactors corresponding to gears, and switching among the gears is realized; and the method utilizes an auxiliary circuit for performing arc quenching and current commutation operations at a moment that the gearsare switched, and the auxiliary circuit is composed of three thyristor groups taking antiparallel thyristors as the basis as well as a transition resistor and each contact. The system provided by theinvention has a switch motion and does not need a time control circuit, and a contact action time sequence is realized by a telescopic moving contact; a thyristor circuit exits after switching is completed and does not carry current for a long time, so that on-state loss of the thyristor circuit is reduced, and life is prolonged; and even if the system is out of control, the contactors still can be used. A tap has a high switch motion speed, arcing is avoided, burning loss of a tapping contact due to the arcing is prevented, and a maintenance period of an on-load tap switch is prolonged, and reliability is improved.