A communication method and apparatus are disclosed for use in vehicle-to-everything (V2X) communications. The method includes: determining a first slot in a resource selection window, where the first slot is used to transmit a first reference signal, the resource selection window includes at least one slot, and the first slot is an unreserved slot, or the first slot is a slot reserved for transmitting a second reference signal; and sending first indication information indicating the first slot. Therefore, a same slot is not shared with a resource for data transmission, so that transmission of the first reference signal in the first slot does not interfere with data transmission in the first slot, thereby ensuring reliability of data transmission.