Embodiments of the present invention provide an RNC migration method, an RNC, and an RNC migration system, wherein a source RNC sends a secure mode instruction to a UE by means of a second SRB to enable the UE to enable integrity protection, and sends a migration request message to a core network when determining that there is no data transmission on a downlink direction of a first SRB of the UE, to enable the core network to migrate a serving RNC of the UE from the source RNC to a target RNC.
