A data packet transmission method, comprising: obtaining, by a terminal, N application programs running on the terminal, wherein N is an integer greater than 0; and if the N application programs comprise an application program comprising a low-latency service, determining whether an unlicensed frequency band is in a congestion state or not; if the unlicensed frequency band is in a congestion state, instructing a network device to schedule a data packet of the terminal to a licensed frequency band for transmission; characterized by the determining, by the terminal, that the N application programs comprise an application program comprising a low-latency service comprises: collecting, by the terminal in a preset period, statistics about a quantity of uplink data packets of each of the N application programs, and if a quantity of uplink data packets of at least one of the N application programs is greater than a first threshold, determining that the application program comprising a low-latency service is running on the terminal; or collecting, by the terminal in a preset period, statistics about a quantity of downlink data packets of each of the N application programs, and if a quantity of downlink data packets of at least one of the N application programs is greater than a second threshold, determining that the application program comprising a low-latency service is running on the terminal; or collecting, by the terminal in a preset period, statistics about a quantity of sockets used by each of the N application programs, and if a quantity of sockets used by at least one of the N application programs is greater than a third threshold, determining that the application program comprising a low-latency service is running on the terminal; or collecting, by the terminal in a preset period, statistics about a data transmission rate of a data packet of each of the N application programs, and if a data transmission rate of a data packet of at least one of the N application programs is greater than a fourth threshold, determining that the application program comprising a low-latency service is running on the terminal. obtaining, by a terminal, N application programs running on the terminal, wherein N is an integer greater than 0; and if the N application programs comprise an application program comprising a low-latency service, determining whether an unlicensed frequency band is in a congestion state or not; if the unlicensed frequency band is in a congestion state, instructing a network device to schedule a data packet of the terminal to a licensed frequency band for transmission; characterized by the determining, by the terminal, that the N application programs comprise an application program comprising a low-latency service comprises: collecting, by the terminal in a preset period, statistics about a quantity of uplink data packets of each of the N application programs, and if a quantity of uplink data packets of at least one of the N application programs is greater than a first threshold, determining that the application program comprising a low-latency service is running on the terminal; or collecting, by the terminal in a preset period, statistics about a quantity of downlink data packets of each of the N application programs, and if a quantity of downlink data packets of at least one of the N application programs is greater than a second threshold, determining that the application program comprising a low-latency service is running on the terminal; or collecting, by the terminal in a preset period, statistics about a quantity of sockets used by each of the N application programs, and if a quantity of sockets used by at least one of the N application programs is greater than a third threshold, determining that the application program comprising a low-latency service is running on the terminal; or collecting, by the terminal in a preset period, statistics about a data transmission rate of a data packet of each of the N application programs, and if a data transmission rate of a data packet of at least one of the N application programs is greater than a fourth threshold, determining that the application program comprising a low-latency service is running on the terminal. collecting, by the terminal in a preset period, statistics about a quantity of uplink data packets of each of the N application programs, and if a quantity of uplink data packets of at least one of the N application programs is greater than a first threshold, determining that the application program comprising a low-latency service is running on the terminal; or collecting, by the terminal in a preset period, statistics about a quantity of downlink data packets of each of the N application programs, and if a quantity of downlink data packets of at least one of the N application programs is greater than a second threshold, determining that the application program comprising a low-latency service is running on the terminal; or collecting, by the terminal in a preset period, statistics about a quantity of sockets used by each of the N application programs, and if a quantity of sockets used by at least one of the N application programs is greater than a third threshold, determining that the application program comprising a low-latency service is running on the terminal; or collecting, by the terminal in a preset period, statistics about a data transmission rate of a data packet of each of the N application programs, and if a data transmission rate of a data packet of at least one of the N application programs is greater than a fourth threshold, determining that the application program comprising a low-latency service is running on the terminal.