An ultra-wideband antenna structure is provided. The ultra-wideband antenna structure includes a substrate with an edge, a first surface and a second surface opposite to the first surface; a ground surface mounted on the first surface; a radiating element mounted on the second surface and near the edge, and being a bent metal piece; and a short-circuited metal unit mounted on the first surface having a first end and a second end, wherein the first end is electrically connected to the ground surface and the second end is electrically connected to the radiating element.