A data processing method, comprising: obtaining, by a terminal device, first information, wherein the first information is used to determine a processing manner of an application data packet in a fourth mode, and the processing manner is transmitting the application data packet in the fourth mode through a packet data unit PDU session for transmitting an application data packet in a first mode, or transmitting the application data packet in the fourth mode through a PDU session for transmitting only the application data packet in the fourth mode; and processing, by the terminal device, the application data packet in the fourth mode in the processing manner, wherein the first mode is a session and service continuity, SSC, mode 1; wherein the fourth mode represents a feature of data transmission of an application and a feature of service continuity of a PDU session; wherein the application data packet in the fourth mode comprises at least one of the following: an application data packet having no mode information, and an application data packet supporting a local access network; wherein the obtaining, by the terminal device, the first information comprises: receiving, by the terminal device, the first information sent by a network device; wherein the first information indicates network information, the network information being used to indicate a network architecture supported by the terminal device; and wherein the terminal device determines, by using the network information, the processing manner of the application data packet in the fourth mode corresponding to the network architecture. obtaining, by a terminal device, first information, wherein the first information is used to determine a processing manner of an application data packet in a fourth mode, and the processing manner is transmitting the application data packet in the fourth mode through a packet data unit PDU session for transmitting an application data packet in a first mode, or transmitting the application data packet in the fourth mode through a PDU session for transmitting only the application data packet in the fourth mode; and processing, by the terminal device, the application data packet in the fourth mode in the processing manner, wherein the first mode is a session and service continuity, SSC, mode 1; wherein the fourth mode represents a feature of data transmission of an application and a feature of service continuity of a PDU session; wherein the application data packet in the fourth mode comprises at least one of the following: an application data packet having no mode information, and an application data packet supporting a local access network; wherein the obtaining, by the terminal device, the first information comprises: receiving, by the terminal device, the first information sent by a network device; wherein the first information indicates network information, the network information being used to indicate a network architecture supported by the terminal device; and wherein the terminal device determines, by using the network information, the processing manner of the application data packet in the fourth mode corresponding to the network architecture. an application data packet having no mode information, and an application data packet supporting a local access network; wherein the obtaining, by the terminal device, the first information comprises: receiving, by the terminal device, the first information sent by a network device; wherein the first information indicates network information, the network information being used to indicate a network architecture supported by the terminal device; and wherein the terminal device determines, by using the network information, the processing manner of the application data packet in the fourth mode corresponding to the network architecture. receiving, by the terminal device, the first information sent by a network device; wherein the first information indicates network information, the network information being used to indicate a network architecture supported by the terminal device; and wherein the terminal device determines, by using the network information, the processing manner of the application data packet in the fourth mode corresponding to the network architecture.