Embodiments of the present invention disclose a packet processing method, device, and system. The system includes: a controller, configured to: allocate a service label to a service processing manner of an FEC, establish a mapping relationship between the service label and the service processing manner, send the service label to a source node, and send the mapping relationship to a destination node; the source node, configured to: receive the service label sent by the controller, receive a first packet, insert the service label to the first packet to obtain a second packet, and send the second packet to the destination node; the destination node, configured to: receive the mapping relationship sent by the controller, receive the second packet sent by the source node, and pop the service label from the second packet according to the mapping relationship, to obtain the first packet. The service label is used for instructing, in a process of forwarding the second packet from the source node to the destination node, a network device that needs to perform service processing on the second packet to process the second packet in the service processing manner.