Embodiments of this application provide a data compression method, including: performing first processing on π/2-binary phase shift keying BPSK modulated data with a length of M, to obtain first frequency domain data with a length of M, where the first processing includes Fourier transform, and M is an even number; performing second processing on second frequency domain data with a length of Q, to obtain time domain data, where data in the second frequency domain data is included in the first frequency domain data, Q is a positive integer, M is greater than Q, Q is greater than or equal to M/2, and the second processing includes inverse Fourier transform; and sending the time domain data on one time domain symbol.