A data compression method, comprising: 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, wherein the first processing comprises 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, wherein data in the second frequency domain data is comprised 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 comprises inverse Fourier transform; and sending the time domain data on one time domain symbol, wherein that data in the second frequency domain data is comprised in the first frequency domain data comprises: a q th piece of frequency domain data in the second frequency domain data is an M − Q + 1 / 2 + q th piece of frequency domain data in the first frequency domain data; or a q th piece of frequency domain data in the second frequency domain data is an M − Q / 2 + q th piece of frequency domain data in the first frequency domain data; or a q th piece of frequency domain data in the second frequency domain data is an M − Q / 2 + q th piece of frequency domain data in the first frequency domain data, wherein a value of q is an integer ranging from 0 to Q -1, wherein that the second processing comprises inverse Fourier transform comprises: the second processing sequentially comprises: frequency domain filtering, inverse Fourier transform, and cyclic prefix adding; or inverse Fourier transform, time domain filtering, and cyclic prefix adding, wherein a square root raised cosine, SRRC, filter or a root raised cosine, RRC, filter is used when the frequency domain filtering or the time domain filtering is performed, and a roll-off factor of a used filter is 2 Q M − 1. 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, wherein the first processing comprises 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, wherein data in the second frequency domain data is comprised 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 comprises inverse Fourier transform; and sending the time domain data on one time domain symbol, wherein that data in the second frequency domain data is comprised in the first frequency domain data comprises: a q th piece of frequency domain data in the second frequency domain data is an M − Q + 1 / 2 + q th piece of frequency domain data in the first frequency domain data; or a q th piece of frequency domain data in the second frequency domain data is an M − Q / 2 + q th piece of frequency domain data in the first frequency domain data; or a q th piece of frequency domain data in the second frequency domain data is an M − Q / 2 + q th piece of frequency domain data in the first frequency domain data, wherein a value of q is an integer ranging from 0 to Q -1, wherein that the second processing comprises inverse Fourier transform comprises: the second processing sequentially comprises: frequency domain filtering, inverse Fourier transform, and cyclic prefix adding; or inverse Fourier transform, time domain filtering, and cyclic prefix adding, wherein a square root raised cosine, SRRC, filter or a root raised cosine, RRC, filter is used when the frequency domain filtering or the time domain filtering is performed, and a roll-off factor of a used filter is 2 Q M − 1. a q th piece of frequency domain data in the second frequency domain data is an M − Q + 1 / 2 + q th piece of frequency domain data in the first frequency domain data; or a q th piece of frequency domain data in the second frequency domain data is an M − Q / 2 + q th piece of frequency domain data in the first frequency domain data; or a q th piece of frequency domain data in the second frequency domain data is an M − Q / 2 + q th piece of frequency domain data in the first frequency domain data, wherein a value of q is an integer ranging from 0 to Q -1, wherein that the second processing comprises inverse Fourier transform comprises: the second processing sequentially comprises: frequency domain filtering, inverse Fourier transform, and cyclic prefix adding; or inverse Fourier transform, time domain filtering, and cyclic prefix adding, frequency domain filtering, inverse Fourier transform, and cyclic prefix adding; or inverse Fourier transform, time domain filtering, and cyclic prefix adding, wherein a square root raised cosine, SRRC, filter or a root raised cosine, RRC, filter is used when the frequency domain filtering or the time domain filtering is performed, and a roll-off factor of a used filter is 2 Q M − 1.