Embodiments of the present invention disclose a data packet processing method, a network traffic management method, an apparatus, and a system. If only one TCP connection is established, multiple networks can be used, and used traffic of each network can be controlled. A method thereof includes: acquiring, by a terminal, an aggregation flow table, where the aggregation flow table includes a management policy for managing network traffic of a first network and network traffic of a second network; determining, by the terminal, from the first network and the second network and according to the aggregation flow table, a transmission network used for transmitting a first uplink data packet; and if the terminal determines to transmit the first uplink data packet by using the first network, sending, by the terminal, the first uplink data packet to the first network by using a first network interface card corresponding to the first network, and forwarding the first uplink data packet to a gateway by using the first network; or if the terminal determines to transmit the first uplink data packet by using the second network, sending, by the terminal, the first uplink data packet to the second network by using a second network interface card corresponding to the second network, and forwarding the first uplink data packet to a gateway by using the second network.