The utility model provides a lightening-proof earthing device of a high-voltage line. The lightening-proof earthing device comprises an earth terminal, a plurality of earth bodies, copper wires, and a conducting plate. The conducting plate is laid 0.5 m beneath the ground horizontally. The multiple copper wires are uniformly distributed in the earth bodies; resin films cover the earth bodies; and the multiple earth bodies and the conducting plate laid under the ground horizontally are in an electric contact mode. According to the technical scheme, the lightening-proof earthing device has the following beneficial effects: the current dispersing effect of the lightening-proof earthing is substantially improved; and the earth resistance is reduced. Meanwhile, because of the low graphite cost, the cost of the lightening-proof earthing device is saved.