The present disclosure provides a method and device used for relay wireless communications. A first node transmits a first radio signal, the first radio signal comprises a first message; transmits a third radio signal on a first radio resource; and receives a second radio signal, the second radio signal comprises a second message, the second message is used to indicate the first radio resource; wherein the first message is used to trigger the second message, and the first radio resource is used for a non-competitive random access. In the L2 relay communication architecture of the present disclosure, the first node acquires a UL synchronization through a non-competitive random access procedure, which can effectively support transmitting end-to-end control information of the PHY layer or the higher layer via a Uu interface.