Device-to-device (d2d) transmission method and device

Provided are a device-to-device (D2D) transmission method and device, wherein the method includes: a device searching for a first synchronizing signal, and determining whether to send a second synchronizing signal according to a search result; on the basis of searching for the first synchronizing signal, the device determining a resource for D2D transmission; and transmitting D2D signals and/or D2D data on the resource. The present invention solves the problem existing in the prior art that the D2D discovery between devices under the scenarios of half coverage and out of coverage is unable to be realized, thereby achieving the effect of D2D discovery between devices.