A data sending method, comprising: performing Fourier transform on a first time domain sequence to obtain a first frequency domain sequence, wherein the first time domain sequence is a Zadoff-Chu sequence, a Frank sequence, a Golomb multiphase sequence, or a Chirp sequence, and a length N of the first time domain sequence corresponds to a quantity of consecutive available subcarriers or a quantity of subcarriers included in a resource block; determining, according to a maximum multipath delay of a system transmission channel, bandwidth of the channel, and a subcarrier quantity N FFT, a maximum quantity of spatial flows that can be supported by a single Orthogonal Frequency Division Multiplexing, OFDM, symbol, comprising: dividing the subcarrier quantity N FFT by the bandwidth of the channel to obtain an Inverse Discrete Fourier Transform, IDFT, period of an OFDM symbol; and dividing the IDFT period of the OFDM symbol by the maximum multipath delay of the system transmission channel to obtain the maximum quantity of spatial flows that can be supported by a single OFDM symbol; determining, in a parameter configuration table according to a total quantity of spatial flows, a cyclic shift parameter corresponding to each spatial flow, wherein the cyclic shift parameter represents a time sequence shift value of the first time domain sequence; obtaining a long training field, LTF, according to the first frequency domain sequence, the maximum quantity of spatial flows, and the cyclic shift parameter, comprising obtaining a second frequency domain sequence of each spatial flow according to the first frequency domain sequence, the maximum quantity of spatial flows, and the cyclic shift parameter, performing inverse Fourier transform on the second frequency domain sequence to obtain a second time domain sequence corresponding to each spatial flow; and adding up the second time domain sequences corresponding to all the spatial flows, to obtain the LTF, wherein the second frequency domain sequence of each spatial flow includes frequency domain sequences of all OFDM symbols of each spatial flow; and sending the LTF and indication information to each receive end, wherein the indication information comprises a number of a spatial flow allocated to each receive end. performing Fourier transform on a first time domain sequence to obtain a first frequency domain sequence, wherein the first time domain sequence is a Zadoff-Chu sequence, a Frank sequence, a Golomb multiphase sequence, or a Chirp sequence, and a length N of the first time domain sequence corresponds to a quantity of consecutive available subcarriers or a quantity of subcarriers included in a resource block; determining, according to a maximum multipath delay of a system transmission channel, bandwidth of the channel, and a subcarrier quantity N FFT, a maximum quantity of spatial flows that can be supported by a single Orthogonal Frequency Division Multiplexing, OFDM, symbol, comprising: dividing the subcarrier quantity N FFT by the bandwidth of the channel to obtain an Inverse Discrete Fourier Transform, IDFT, period of an OFDM symbol; and dividing the IDFT period of the OFDM symbol by the maximum multipath delay of the system transmission channel to obtain the maximum quantity of spatial flows that can be supported by a single OFDM symbol; determining, in a parameter configuration table according to a total quantity of spatial flows, a cyclic shift parameter corresponding to each spatial flow, wherein the cyclic shift parameter represents a time sequence shift value of the first time domain sequence; obtaining a long training field, LTF, according to the first frequency domain sequence, the maximum quantity of spatial flows, and the cyclic shift parameter, comprising obtaining a second frequency domain sequence of each spatial flow according to the first frequency domain sequence, the maximum quantity of spatial flows, and the cyclic shift parameter, performing inverse Fourier transform on the second frequency domain sequence to obtain a second time domain sequence corresponding to each spatial flow; and adding up the second time domain sequences corresponding to all the spatial flows, to obtain the LTF, wherein the second frequency domain sequence of each spatial flow includes frequency domain sequences of all OFDM symbols of each spatial flow; and sending the LTF and indication information to each receive end, wherein the indication information comprises a number of a spatial flow allocated to each receive end.