A packet processing method includes: a traffic classifier receives a first packet; the traffic classifier determines, in policy information in the traffic classifier and according to a first filtering rule that matches the first packet, a first service identifier that matches the first filtering rule, and an address, which matches the first filtering rule, of a first service routing trigger. The traffic classifier sends a second packet to the first service routing trigger. Where the policy information includes: a filtering rule, an address of a service routing trigger, and a service identifier corresponding to the filtering rule. Where the filtering rule is used to identify a packet, and the service identifier is used to represent a sequence of a service node that processes the packet. Where the second packet is formed by adding the first service identifier to the first packet.