Data exchange method and device

The invention provides a data exchange method and device, relates to the technical field of communication, and is used for improving the exchange efficiency of a data exchange network and reducing the exchange time delay. The method comprises: a source node receives flow indication information from a first switching node, the flow indication information being used for indicating that a target data flow is congested, and the first switching node being a node in a switching path of the target data flow; the source node sends a plurality of pieces of write data information and a plurality of data blocks of a target data stream to a plurality of switching nodes, wherein the plurality of pieces of write data information are used for indicating the plurality of switching nodes to store the plurality of data blocks and stop forwarding the plurality of data blocks; the plurality of switching nodes store the plurality of data blocks according to the plurality of pieces of write data information; the plurality of switc