Embodiments of the present application provide a method and a device for wireless communication, which can balance the relationship between resource utilization and transmission reliability. The method includes: a network device determines a transmission mode of a packet data convergence protocol PDCP protocol data unit PDU, where the transmission mode includes a duplicate data transmission mode or a single link transmission mode; and the network device transmits the PDCP PDU to the terminal according to the transmission mode of the PDCP PDU.