A mobility management method, performed by User Equipment, UE, comprising: receiving core network information about each cell from a network side device, the core network information being used to indicate a type of a core network; and performing cell reselection in accordance with the type of the core network for each cell and a capability of a User Equipment, UE, for supporting the core network when the UE is in an idle state; characterized in that the core network information transmitted by the network side device in a source cell is further used to indicate cell priority information, the performing cell reselection in accordance with the type of the core network for each cell and a capability of the UE for supporting the core network when the UE is in the idle state comprises: reading the received core network information so as to acquire a type of a core network and cell priority information corresponding to each to-be-attached cell; measuring Reference Signal Received Power, RSRP, of each to-be-attached cell in accordance with reselected parameter information of the UE; ranking network reselection priority levels of the to-be-attached cells in accordance with the cell priority information and the RSRP of each to-be-attached cell, so as to determine a first target cell for attachment; determining whether the UE is capable of being attached to the first target cell in accordance with the capability of the UE for supporting the core network; and when the UE is incapable of being attached to the first target cell, ranking the network reselection priority levels of the to-be-attached cells corresponding to the type of the core network capable of being supported by the UE, so as to determine a second target cell for attachment. receiving core network information about each cell from a network side device, the core network information being used to indicate a type of a core network; and performing cell reselection in accordance with the type of the core network for each cell and a capability of a User Equipment, UE, for supporting the core network when the UE is in an idle state; characterized in that the core network information transmitted by the network side device in a source cell is further used to indicate cell priority information, the performing cell reselection in accordance with the type of the core network for each cell and a capability of the UE for supporting the core network when the UE is in the idle state comprises: reading the received core network information so as to acquire a type of a core network and cell priority information corresponding to each to-be-attached cell; measuring Reference Signal Received Power, RSRP, of each to-be-attached cell in accordance with reselected parameter information of the UE; ranking network reselection priority levels of the to-be-attached cells in accordance with the cell priority information and the RSRP of each to-be-attached cell, so as to determine a first target cell for attachment; determining whether the UE is capable of being attached to the first target cell in accordance with the capability of the UE for supporting the core network; and when the UE is incapable of being attached to the first target cell, ranking the network reselection priority levels of the to-be-attached cells corresponding to the type of the core network capable of being supported by the UE, so as to determine a second target cell for attachment. reading the received core network information so as to acquire a type of a core network and cell priority information corresponding to each to-be-attached cell; measuring Reference Signal Received Power, RSRP, of each to-be-attached cell in accordance with reselected parameter information of the UE; ranking network reselection priority levels of the to-be-attached cells in accordance with the cell priority information and the RSRP of each to-be-attached cell, so as to determine a first target cell for attachment; determining whether the UE is capable of being attached to the first target cell in accordance with the capability of the UE for supporting the core network; and when the UE is incapable of being attached to the first target cell, ranking the network reselection priority levels of the to-be-attached cells corresponding to the type of the core network capable of being supported by the UE, so as to determine a second target cell for attachment.