The present disclosure discloses a dynamic spectrum allocation method and device based on channel management. The method comprises the following steps: a network node generates a channel set according to an available channel list and channel classification information, and maintains and updates the channel set; and the network node selects a spectrum from the channel set and allocates the spectrum. The device comprises: a channel set generation module configured to generate a channel set according to an available channel list and channel classification information and maintain and update the channel set; and a spectrum allocation module configured to select a spectrum from the channel set and allocate the spectrum. The present disclosure can reduce the delay in the spectrum resource reconfiguration of a CR system, improves the overall performance of spectrum resource reconfiguration and increases the utilization efficiency of a spectrum.