The invention relates to a signal forwarding device and a signal forwarding method. The signal forwarding device comprises a processing chip and a signal dismantling unit. The processing chip definesa sign downloading period and a signal uploading period according to a frequency signal. The signal dismantling unit is connected with the processing chip to shunt a wired downloading signal from a wireless downloading signal transmitted by a base station during the sign downloading period accordingly, and transmit the wireless downloading signal and the wired downloading signal to a correspondingdownstream device respectively; and the signal dismantling unit integrates a wired uploading signal and a wireless uploading signal transmitted by the downstream device and transmits the integrated wireless uploading signal to the base station in the signal uploading period. Therefore, the signal forwarding device can simultaneously achieve the effects of a modem and a repeater.