One embodiment of the present invention is a device-to-device (D2D) communication method. According to said method, a first terminal performs D2D communication with a second terminal in a wireless communication system, and comprises the steps of: receiving a first signal from the second terminal; and transmitting a second signal based on the received first signal to a third terminal. The first signal and the second signal are used in acquiring synchronization related to the D2D communication in each of the first terminal and the third terminal.