A remote access device and a method for shaping the spectrum of output signal are disclosed, and the method includes: obtaining a power spectrum density of a signal transmitted by a Central Office (CO) access device at a remote access device; dividing a spectrum of an output signal of the remote access device into a spectrum overlapping portion and a spectrum non-overlapping portion according to the power spectrum density of the signal transmitted by the CO access device; and shaping the power spectrum density of the output signal in the spectrum overlapping portion according to the power spectrum density of the signal transmitted by the CO access device. In accordance with the embodiment of the present invention, it is possible to automatically or manually set the spectrum of downlink signal of CO access device at the remote access device, which maximizes the spectrum utilization ratio of remote access device, and it is possible to get the better transmission performance in accordance with the embodiment of the present invention.