The invention discloses an anti-thunder down-conductor bridging structure and a construction method thereof, and relates to the technical field of anti-thunder down-conductor bridging processing. Theanti-thunder down-conductor bridging structure comprises a main rib, a connecting sleeve and a bridging sleeve which are arranged in order from the inside to the outside. The main rib comprises at least two steel bars which are adjacent to each other in the vertical direction and connected through the connecting sleeve. A part of the bridging sleeve at the upper end of the connecting sleeve and apart of the bridging sleeve at the lower end of the connecting sleeve are both in interference fit with the main rib. The construction method comprises the steps of firstly installing the bridging sleeve; then squeezing the part of the bridging sleeve at the upper end of the connecting sleeve and the part of the bridging sleeve at the lower end of the connecting sleeve in order that the part of the bridging sleeve at the upper end of the connecting sleeve and the part of the bridging sleeve at the lower end of the connecting sleeve are both in interference fit with the main rib. The anti-thunder down-conductor bridging structure is simple in structure, avoids welding, improves the strength and durability of the main rib, is not affected by the welding skill of a welding worker, improves the stability of a bridging treatment effect, and improves the conductive effect of the main rib.