Abstract: This application provides a method for transmitting data streams. The data streams include a first data stream whose encoded form is a fountain code. A first intermediate node receives an encoded packet sent by a source node or a second intermediate node, where the encoded packet is a packet obtained by encoding an original packet of the first data stream with a fountain code technology. The first intermediate node drops the encoded packet in case of usage of a first cache queue exceeds a threshold, where the first cache queue is a cache queue in the first intermediate node and is allocated to the first data stream.