Data transmission method and device

The invention provides a data transmission method and a data transmission device, which are used for realizing inter-stream synchronization of different data streams received by different host end devices. The method comprises: a first device sends a first message to a second device and sends a second message to a third device, the first message comprising a first data stream and a sampling time sequence of the first data stream; the second message comprises a second data stream and a sampling time sequence of the second data stream, and the first message and the second message correspond to a first communication protocol; the sampling time sequence of the first data stream and the sampling time sequence of the second data stream are time sequences taking a codec system clock of the first equipment as a unit value; the first equipment sends a third message to the second equipment and third equipment, the third message comprises a first timestamp and a second timestamp, the first timestamp is used for indicati