A data routing method and apparatus resolve a problem that data packet forwarding efficiency is greatly reduced because a service function instance sequence needs to be retrieved for each data packet according to a 5-tuple of a data flow to which the data packet belongs. The data routing method includes: receiving, by a traffic classifier, a data packet, where the data packet belongs to a first data flow; allocating, by the traffic classifier, a first data route identifier to the first data flow, where the first data route identifier is used to identify a service function chain of the first data flow and is used to identify the first data flow; adding, by the traffic classifier, the first data route identifier to the data packet; and sending, by the traffic classifier, the data packet to a service function forwarding device.