A broadband test line-access unit, including a first test terminal, a second test terminal, a third test terminal, a signal splitter, a first switch, a second switch, a third switch, a first interface terminal, a second interface terminal and a third interface terminal. A broadband test line-access board, including at least two broadband test line-access units, a set of internal test buses, a fourth switch, a fifth switch and a sixth switch, the set of internal test buses including an internal inner-test bus, an internal outer-test bus and an internal auxiliary-test bus. A broadband test device, including at least one broadband test line-access boards, an eighth switch, a ninth switch, a test control module. The broadband test device is of simple structure and low cost, facilitates a port level N+1 backup function within a board, and thus can provide improved communication reliability.