In a data transmission control method, one or more pieces of identification information are added to determine an interface resource object for forwarding a data packet on an interface of a network device. The added one or more pieces of identification information include one piece of global identification information. The global identification information may correspond to a network slice, and different network slices correspond to different values of global identification information. A global network identifier corresponds to one or more interface resource objects. One interface resource object may be occupied by one network slice alone, or one interface resource object may be jointly shared by a plurality of network slices.