A communication method and apparatus are disclosed, and are applicable to fields such as V2X, the internet of vehicles, intelligent networked vehicles, driver assistance, and intelligent driving. The method includes: A terminal device determines that uplink transmission and sidelink transmission both exist; and when one or more of a first condition, a second condition, a third condition, and a fourth condition are not met, the terminal device performs the sidelink transmission; or when any one of one or more of a first condition, a second condition, a third condition, and a fourth condition is met, the terminal device performs the uplink transmission.