Data stream transmission method, device and system

The present invention relates to the field of communications. Disclosed are a data stream transmission method, device and system, which can solve the problem that resources are wasted when a relay user equipment provides a relay service to a remote user equipment. The specific solution comprises: a first network device triggers a first relay user equipment to establish a common data stream bearer with a second network device, and before or after the first network device triggers the first relay user equipment to establish the common data stream bearer with the second network device, the first network device sends a common data stream identifier to a remote user equipment in a first group. The present invention is used for data stream transmission.