A node handover method applied to a controller in a software defined protocol, SDP, network system, wherein the method comprises: receiving (201, 413, 513, 613, 713, 813, 913) a protocol configuration request message sent by a target access node, wherein the protocol configuration request message comprises a quality of service parameter of user equipment, UE, the protocol configuration request message is generated by the target access node according to a handover request message sent by a source access node, the source access node is a node accessed by the UE before node handover, and the target access node is a node accessed by the UE after node handover; determining (202, 414, 514, 614, 714, 814, 914), according to the quality of service parameter, a function module corresponding to a service of the UE to process the service of the UE, wherein the function module corresponding to the service of the UE is configured at one or more protocol layers; determining, according to the function module corresponding to the service of the UE and a network topology, a target node that bears the function module corresponding to the service of the UE after node handover, wherein the target node comprises the target access node and a node of the target node is able to send a data stream to a gateway, the network topology comprises a connection relationship among multiple nodes in the SDP network system and a function module of each node in the SDP network system; configuring (203, 415, 416, 515, 516, 615, 715, 716, 815, 816, 915), according to the function module corresponding to the service of the UE and the network topology, a function module for the target node to implement a data stream exchange between the UE and the gateway; determining (204, 417, 517, 616, 717, 916), according to the function module configured for the target node and the network topology, a first forwarding entry group required for data stream transmission between a source node and the target node, wherein the source node comprises the source access node, and the source node is configured by the controller to bear the function module corresponding to the service of the UE before node handover to implement data stream exchange between the UE and the gateway; and determining (205, 421, 520, 620, 719, 817), according to the function module configured for the target node and the network topology, a second forwarding entry group required for data stream transmission between the gateway and any node of the target node. receiving (201, 413, 513, 613, 713, 813, 913) a protocol configuration request message sent by a target access node, wherein the protocol configuration request message comprises a quality of service parameter of user equipment, UE, the protocol configuration request message is generated by the target access node according to a handover request message sent by a source access node, the source access node is a node accessed by the UE before node handover, and the target access node is a node accessed by the UE after node handover; determining (202, 414, 514, 614, 714, 814, 914), according to the quality of service parameter, a function module corresponding to a service of the UE to process the service of the UE, wherein the function module corresponding to the service of the UE is configured at one or more protocol layers; determining, according to the function module corresponding to the service of the UE and a network topology, a target node that bears the function module corresponding to the service of the UE after node handover, wherein the target node comprises the target access node and a node of the target node is able to send a data stream to a gateway, the network topology comprises a connection relationship among multiple nodes in the SDP network system and a function module of each node in the SDP network system; configuring (203, 415, 416, 515, 516, 615, 715, 716, 815, 816, 915), according to the function module corresponding to the service of the UE and the network topology, a function module for the target node to implement a data stream exchange between the UE and the gateway; determining (204, 417, 517, 616, 717, 916), according to the function module configured for the target node and the network topology, a first forwarding entry group required for data stream transmission between a source node and the target node, wherein the source node comprises the source access node, and the source node is configured by the controller to bear the function module corresponding to the service of the UE before node handover to implement data stream exchange between the UE and the gateway; and determining (205, 421, 520, 620, 719, 817), according to the function module configured for the target node and the network topology, a second forwarding entry group required for data stream transmission between the gateway and any node of the target node.