A device-to-device (D2D) communication method and a D2D terminal device, where the method includes determining, by a first device, a time that the first device is out of coverage of a synchronization source after leaving the coverage of the synchronization source determining, by the first device, target timing based on the time, and performing, by the first device, D2D communication based on the target timing. Hence, the target timing can be selected more accurately for the first device.