Embodiments of the present invention disclose a reference signal transmission method. A transmitting apparatus multiplies M first symbol sequences by M coefficients respectively to obtain M second symbol sequences, where M is a positive integer greater than 1, the symbol sequence includes L symbols, L is a positive integer greater than 1, and the M coefficients each have a magnitude of 1. The transmitting apparatus maps the M second symbol sequences onto a first time-frequency resource to obtain a frequency domain signal. The transmitting apparatus performs an IFFT operation on the frequency domain signal to obtain a time domain signal. And the transmitting apparatus sends the time domain signal.