Disclosed in the invention is a parallel type automatic compensation apparatus for an arc-suppression coil. The automatic compensation apparatus is composed of a Z type transformer, an arc-suppression coil, a damping resistor, capacitance regulating units, inductance regulating units, a line selection resistor, silicon controlled rectifier switches, and a microcomputer controller. When a single-phase ground fault occurs at a system, the ground capacitance current of the system can be compensated rapidly; and the line selection function is realized. Meanwhile, the compensation capacity of the arc-suppression coil can be adjusted in real time according to the change of the ground capacitance current of the system; and no heavy closing inrush current is generated when capacitor switching is carried out, thereby avoiding the adverse effect on the capacitor. Besides, the heavy inductive current can be provided by using the small-capacity inductor, thereby lowering the cost and reducing the occupied area. Moreover, the capacitors and inductors are connected in parallel to a secondary winding of the arc-suppression coil, so that the regulating range of the arc-suppression coil can be increased and easy capacity expanding can be realized. Therefore, the automatic compensation apparatus has advantages of wide regulating range, high capacity expanding, fast compensation speed, improved power supply safety and reliability of the power distribution network, and high practicability.