A network traffic migration method, wherein the method comprises: obtaining a bandwidth usage parameter value of each of M virtual broadband network gateway user plane, vBNG-UP, network elements, wherein M is an integer greater than 1; when a bandwidth usage parameter value of a first vBNG-UP network element reaches a first threshold, determining a second vBNG-UP network element based on a sum of bandwidths occupied by to-be-migrated network traffic of one or more terminal devices in a first device group on the first vBNG-UP network element and a bandwidth usage parameter value of one or more vBNG-UP network elements in a vBNG-UP network element group, wherein the first vBNG-UP network element and the second vBNG-UP network element are vBNG-UP network elements in the M vBNG-UP network elements, and the vBNG-UP network element group comprises vBNG-UP network elements in the M vBNG-UP network elements except the first vBNG-UP network element; and migrating the to-be-migrated network traffic of the terminal devices in the first device group to the second vBNG-UP network element; wherein the determining a second vBNG-UP network element comprises: when a bandwidth usage parameter value of a first interface on the first vBNG-UP network element reaches the first threshold, predicting, based on the sum of bandwidths occupied by the network traffic of the terminal devices in the first device group and a bandwidth usage parameter value of a second interface, a bandwidth usage parameter value of the second interface that exists after the network traffic of the terminal devices in the first device group is migrated to the second interface; and when the predicted bandwidth usage parameter value reaches a second threshold, determining that a vBNG-UP network element on which the second interface is located is the second vBNG-UP network element, wherein the second interface is an interface on a vBNG-UP network element in the vBNG-UP network element group, and the network traffic of the terminal devices in the first device group is network traffic transmitted on the first interface. obtaining a bandwidth usage parameter value of each of M virtual broadband network gateway user plane, vBNG-UP, network elements, wherein M is an integer greater than 1; when a bandwidth usage parameter value of a first vBNG-UP network element reaches a first threshold, determining a second vBNG-UP network element based on a sum of bandwidths occupied by to-be-migrated network traffic of one or more terminal devices in a first device group on the first vBNG-UP network element and a bandwidth usage parameter value of one or more vBNG-UP network elements in a vBNG-UP network element group, wherein the first vBNG-UP network element and the second vBNG-UP network element are vBNG-UP network elements in the M vBNG-UP network elements, and the vBNG-UP network element group comprises vBNG-UP network elements in the M vBNG-UP network elements except the first vBNG-UP network element; and migrating the to-be-migrated network traffic of the terminal devices in the first device group to the second vBNG-UP network element; wherein the determining a second vBNG-UP network element comprises: when a bandwidth usage parameter value of a first interface on the first vBNG-UP network element reaches the first threshold, predicting, based on the sum of bandwidths occupied by the network traffic of the terminal devices in the first device group and a bandwidth usage parameter value of a second interface, a bandwidth usage parameter value of the second interface that exists after the network traffic of the terminal devices in the first device group is migrated to the second interface; and when the predicted bandwidth usage parameter value reaches a second threshold, determining that a vBNG-UP network element on which the second interface is located is the second vBNG-UP network element, wherein the second interface is an interface on a vBNG-UP network element in the vBNG-UP network element group, and the network traffic of the terminal devices in the first device group is network traffic transmitted on the first interface. when a bandwidth usage parameter value of a first interface on the first vBNG-UP network element reaches the first threshold, predicting, based on the sum of bandwidths occupied by the network traffic of the terminal devices in the first device group and a bandwidth usage parameter value of a second interface, a bandwidth usage parameter value of the second interface that exists after the network traffic of the terminal devices in the first device group is migrated to the second interface; and when the predicted bandwidth usage parameter value reaches a second threshold, determining that a vBNG-UP network element on which the second interface is located is the second vBNG-UP network element, wherein the second interface is an interface on a vBNG-UP network element in the vBNG-UP network element group, and the network traffic of the terminal devices in the first device group is network traffic transmitted on the first interface.