A method for transmitting a data frame performed by a station, comprising: acquiring, by the station, long training field, LTF, parameters, and acquiring a start position I of allocated subcarriers; performing, by the station, according to a frequency domain transform parameter and the start position I, a frequency domain transform on an LTF basic sequence to obtain an LTF symbol; performing, according to a number of spatial streams N, a spread spectrum processing on the LTF symbol to obtain an LTF sequence; sending a data frame, wherein the data frame comprises the LTF sequence and indication information, wherein the LTF basic sequence is allocated by the station, wherein a mapping relationship table is preconfigured in the station, wherein when a mapping relationship table is preconfigured using a manner 1, the station directly acquires the stored LTF basic sequence, wherein when the mapping relationship table is preconfigured in the station using any one of a manner 2, a manner 3, or a manner 4, after the station acquires the LTF parameters, the station selects from prestored LTF basic sequences, according to the frequency domain transform parameter included in the LTF parameters, an LTF basic sequence that needs to be used, wherein in a manner 1, the mapping relationship table includes a quantity N SS of multiplexed spatial streams, a type of an access point, AP, and parameters corresponding to the quantity N SS and the type of the AP, wherein the quantity N SS of multiplexed spatial streams is a quantity of data streams in single-user multiplexing, wherein in a manner 2, the mapping relationship table includes a quantity N SS of multiplexed spatial streams, a type of an environment in which the AP is located, and parameters corresponding to the quantity N SS and the type of the environment in which the AP is located wherein in a manner 3, the mapping relationship table includes a quantity N SS of multiplexed spatial streams, and parameters corresponding to the quantity N SS, and wherein in a manner 4, the mapping relationship table includes a quantity N SS of multiplexed spatial streams, MCS feature information, and parameters corresponding to the quantity N SS and the MCS feature information. acquiring, by the station, long training field, LTF, parameters, and acquiring a start position I of allocated subcarriers; performing, by the station, according to a frequency domain transform parameter and the start position I, a frequency domain transform on an LTF basic sequence to obtain an LTF symbol; performing, according to a number of spatial streams N, a spread spectrum processing on the LTF symbol to obtain an LTF sequence; sending a data frame, wherein the data frame comprises the LTF sequence and indication information, wherein the LTF basic sequence is allocated by the station, wherein a mapping relationship table is preconfigured in the station, wherein when a mapping relationship table is preconfigured using a manner 1, the station directly acquires the stored LTF basic sequence, wherein when the mapping relationship table is preconfigured in the station using any one of a manner 2, a manner 3, or a manner 4, after the station acquires the LTF parameters, the station selects from prestored LTF basic sequences, according to the frequency domain transform parameter included in the LTF parameters, an LTF basic sequence that needs to be used, wherein in a manner 1, the mapping relationship table includes a quantity N SS of multiplexed spatial streams, a type of an access point, AP, and parameters corresponding to the quantity N SS and the type of the AP, wherein the quantity N SS of multiplexed spatial streams is a quantity of data streams in single-user multiplexing, wherein in a manner 2, the mapping relationship table includes a quantity N SS of multiplexed spatial streams, a type of an environment in which the AP is located, and parameters corresponding to the quantity N SS and the type of the environment in which the AP is located wherein in a manner 3, the mapping relationship table includes a quantity N SS of multiplexed spatial streams, and parameters corresponding to the quantity N SS, and wherein in a manner 4, the mapping relationship table includes a quantity N SS of multiplexed spatial streams, MCS feature information, and parameters corresponding to the quantity N SS and the MCS feature information.