Abstract: This present invention discloses a type of active and standby board backup and switchover method for access devices, comprising: maintain real time communications between standby board and active board, and check the operating status of the active board at all times; refresh standby board data based on changes to multicast client dynamic data in the active board; perform switchover from the active board to the standby board based on the active board failure detected; the new active board sends a multicast join request to the upstream router based on its saved data. Multicast client dynamic data comprises: multicast client online record, multicast client CDR (Call Detail Record), etc. Adopting the method of this invention guarantees that clients remain online during switchover, ensures an uninterrupted video stream, and thereby ensures that the switchover from active to standby does not significantly affect multicast services for multicast clients.