Embodiments of the present invention disclose a modulation method and apparatus. The modulation method includes: processing at least two data blocks, and outputting at least two single-carrier Orthogonal Frequency Division Multiplex (OFDM) signals, where the at least two data blocks include a first data block and a second data block, the at least two single-carrier OFDM signals include a first single-carrier OFDM signal corresponding to the first data block and a second single-carrier OFDM signal corresponding to the second data block, a difference between a carrier center frequency RF1 of the first single-carrier OFDM signal and a carrier center frequency RF2 of the second single-carrier OFDM signal is an integral multiple of an F0, and the F0 is a subcarrier bandwidth; and transmitting the at least two single-carrier OFDM signals.