The invention relates to a portable ground wire connection device for a substation and a use method. Insulating rods are raised with two hands, clamping and embedding parts are hooked on an alternating current phase line of a substation line, the insulating rods are downwards pulled, the alternating current phase line is clamped in two elastic pieces of the clamping and embedding parts to be contacted with sharp teeth, the insulating rods are downwards pulled, connectors II are separated from connectors I, the clamping and embedding parts of the connectors II are firmly suspended on the alternating current phase line of the substation line, ground wire connection can be completed, and overhaul or detection work is performed; when a ground wire is removed, the insulating rods are raised with two hands, the connectors I on the insulating rods are attracted with connectors together, the insulating rods are upwards raised, and the alternating current phase line is separated from the clamping and embedding parts. The portable ground wire connection device is simple in structure and convenient to use and carry, can be used no matter whether oxidation layers exist on the line and whether the line is covered with ice, good contact of a bus with the ground wire of the line can be ensured, sudden electricity supply and static electricity supply due to induction can be prevented, and personal safety of workers on power failure equipment and the line is guaranteed.