This application discloses a signal transmission method, including: obtaining, by a terminal device, to-be-transmitted data, uplink control information, and a demodulation reference signal; mapping the to-be-transmitted data, the uplink control information, and the demodulation reference signal to generate multiplexed symbols. The multiplexed symbols include DFT-s-OFDM symbols or OFDM symbols. N first multiplexed symbols are located on one side or two sides of a second multiplexed symbol. A location relationship between each of the N first multiplexed symbols and the second multiplexed symbol satisfies a mapping condition. N is an integer greater than or equal to 1. The first multiplexed symbol is a multiplexed symbol to which the uplink control information is mapped, and the second multiplexed symbol is a multiplexed symbol to which the demodulation reference signal is mapped.