Communication method and communications apparatus

This application provides a method includes: If a first terminal device has to-be-sent periodic data, the first terminal device determines a first time unit set. The first terminal device determines that a first time unit in the first time unit set is used to send the periodic data, and determines, from the first time unit set based on a first time domain interval and a reservation quantity N, a second time unit set used to send the periodic data. A time domain interval between the 1st time unit in the second time unit set and the first time unit is the first time domain interval, and a number of a time unit in the second time unit set is greater than that of the first time unit. The method may be used in an internet of vehicles, for example, V2X, LTE-V, or V2V.