Various examples of the present disclosure describe a random access method and device in a CR system. The method includes: generating, by a base station device, a spectrum handover command, wherein the spectrum handover command comprises random access backoff time parameter information; and sending, by the base station device, the spectrum handover command to a user equipment in a cell to instruct the UE to initiate, during a spectrum handover procedure, a random access procedure using the random access backoff time parameter information. According to the various examples of the present disclosure, the random access backoff time parameter information is carried in the spectrum handover command, so that a random access conflict is suppressed during the spectrum handover procedure of the CR system. A large number of UEs that intensively perform random access on a target working frequency are pre-dispersed in time. As such, the delay and the failure probability of the random access on the target working frequency during the spectrum handover procedure are reduced, and thus the failure probability of the spectrum handover and the service interruption time are reduced, so that the user experience of the CR system is improved.