The invention relates to a voltage regulation and dynamic compensation device on the low-voltage side of an arc furnace, which comprises a high-voltage wireless telegauge, a high-voltage switch cabinet, a controller, a contactor, a compensating capacitor, a booster transformer and an arc furnace transformer. The device is characterized in that a booster transformer is arranged on the low-voltage side of the arc furnace transformer, the compensating capacitor is installed on the high-voltage side of the booster transformer, current and voltage signals on the high-voltage side of the arc furnace are gathered through a current transformer in the high-voltage wireless telegauge and a voltage transformer in the high-voltage switch cabinet, the gathered signals are sent into the control to be processed, and switching signals are sent to the contactor in stages to control the switching of the compensating capacitor; and a load is connected between the booster transformer and the arc furnace transformer. The device solves the problem of the reactive compensation from the source of the reactive load, improves the compensation efficiency, greatly reduces the physical volume of the compensation device, and reduces the cost for the system and the floor space.