A communication method and a related apparatus for data transmission in vehicle-to-everything (V2X) communication, the apparatus including at least one processor and a non-transitory computer-readable memory storing a program to be executed by the at least one processor, the program including instructions for obtaining a first parameter value of an uplink, obtaining a second parameter value of a sidelink, and transmitting, according to a comparison between the first parameter value and the second parameter value, at least one of an uplink media access control protocol data unit or a sidelink media access control protocol data unit, where the uplink is a wireless communications link from the apparatus to a network device, and where the sidelink is a wireless direct transmission link between the apparatus and another terminal device.