D2d resource allocation method, device and system

Embodiments of the present invention provide a D2D resource allocation method, device and system, for use in at least resolving the problem of resource allocation for a link from a UE beyond network coverage to a UE within the network coverage. The method comprises: a first UE receives a first message sent by a second UE, the first message being used for requesting allocating resources to the second UE, the first UE being a UE within network coverage of a base station, and the second UE being a UE beyond the network coverage of the base station; the first UE acquires, according to the first message, resource indication information of a first resource allocated to the second UE; and the first UE sends a second message to the second UE, the second message carrying the resource indication information, so that the second UE sends, according to the resource indication information, data to the first UE by using the first resource. The present invention is applicable to the field of wireless communications.