A method for a handover without a default bearer, wherein the method comprises: after a handover process is triggered, a source network device sends a handover request to a first network device, the source network device being either a source eNode B eNB or a source Radio Network Controller RNC sending, by the first network device, a relocation request to a second network device, wherein the relocation request comprises information about a third network device and a forwarding mode identifier, wherein the information about the third network device is used for the second network device to establish a connection to the third network device, and the forwarding mode identifier is used for indicating that after a handover, data of the source network device is to be directly forwarded to a target network device or indirectly forwarded to a target network device, the target network device being either a target eNB or a target RNC; receiving, by the first network device, a relocation response sent by the second network device, wherein the relocation response carries indication information indicating that data is to be forwarded by using a signaling plane; sending, by the first network device, a handover command to the source network device, so that the source network device forwards the data to a target network device by using the signaling plane according to a forwarding mode indicated by the forwarding mode identifier carried in the handover command; and sending, by the first network device, a relocation complete message to the second network device, so that the second network device sends a handover complete notification message to the third network device, and the third network device updates serving node information from an address of the first network device to an address of the second network device. after a handover process is triggered, a source network device sends a handover request to a first network device, the source network device being either a source eNode B eNB or a source Radio Network Controller RNC sending, by the first network device, a relocation request to a second network device, wherein the relocation request comprises information about a third network device and a forwarding mode identifier, wherein the information about the third network device is used for the second network device to establish a connection to the third network device, and the forwarding mode identifier is used for indicating that after a handover, data of the source network device is to be directly forwarded to a target network device or indirectly forwarded to a target network device, the target network device being either a target eNB or a target RNC; receiving, by the first network device, a relocation response sent by the second network device, wherein the relocation response carries indication information indicating that data is to be forwarded by using a signaling plane; sending, by the first network device, a handover command to the source network device, so that the source network device forwards the data to a target network device by using the signaling plane according to a forwarding mode indicated by the forwarding mode identifier carried in the handover command; and sending, by the first network device, a relocation complete message to the second network device, so that the second network device sends a handover complete notification message to the third network device, and the third network device updates serving node information from an address of the first network device to an address of the second network device.