A wave filter is installed in a multimedia wideband router, and includes a circuit board having a first low-pass wave-filtering circuit, and a band-pass wave-filtering circuit; the band-pass wave-filtering circuit consists of a high-pass wave-filtering circuit and a second low-pass wave-filtering circuit; the first low-pass wave-filtering circuit is connected to the high-pass wave-filtering circuit; the circuit board further includes an input terminal, and a first switching component, which is movable to such a position as to electrically connect the input terminal and a joint between the first low-pass wave-filtering circuit and the high-pass wave-filtering circuit; the circuit board further includes two output terminals, which are connected to the first and the second low-pass wave-filtering circuits respectively; a second switching component is provided on the circuit board, which is movable to such a position as to electrically connect the high-pass wave-filtering circuit and the second low-pass wave-filtering circuit.