Embodiments of the present invention provide a retransmission method and device. The method includes: controlling, by a network side device, a network side node to send a second space processing mode to a terminal after the network side node receives a negative acknowledgement fed back by the terminal, where the negative acknowledgement is used to indicate that the terminal fails in decoding the downlink data sent by a first node, the second space processing mode is used to indicate a space processing mode applied by the second node to the downlink data, and the second space processing mode is different from a first space processing mode applied by the first node to the downlink data; and controlling, by the network side device, the second node to perform space processing for the downlink data by using the second space processing mode and then retransmit the downlink data to the terminal.