A reference signal sending/receiving method, a terminal device, and a network device are provided. The terminal device determines transmit power of a reference signal of the terminal device, where the transmit power is related to a quantity of unavailable time-frequency resources in a transmission unit in which the reference signal is located; and transmits the reference signal based on the transmit power. After receiving the reference signal from the terminal device, the network device parses the reference signal based on the transmit power. The terminal device relates the transmit power of the reference signal of the terminal device to the quantity of unavailable time-frequency resources in the transmission unit in which the reference signal is located, thereby improving the transmit power of the reference signal of the terminal device in uplink MU-MIMO, and improving communication performance of the terminal device with a low signal-to-noise ratio.