The invention provides a data traffic processing method, a network device and a network system, wherein the data traffic processing method comprises the steps of: receiving a data traffic message; recognizing protocol information and/or traffic information of the message; mapping the protocol information and/or traffic information to a corresponding traffic type field, and modifying a traffic type value of the message according to the mapped traffic type field; and carrying out queue scheduling and forwarding on the message according to the service type value of the message. The invention hasthe advantages of effectively lowering cost of a QoS (Quality of Service) implementation scheme, preventing a traffic of falsifying high priority by a low-priority application server, and avoiding using the traffic of loading low-priority by using a high-priority port.