The embodiments of the present disclosure provide a method, a device and a system for data stream transmission, which relate to the field of communication, and can reduce the energy consumption of the data stream transmission between devices. The method includes: receiving, by a resting device, a message indicating to enter into an energy-saving state; after receiving the message indicating to enter into the energy-saving state, sending, by the resting device, stored user information to an on-duty device so that the on-duty device receives and synchronizes user information; and, after the user information is synchronized, setting, by the resting device, the transmission state of the resting device as standby and entering into a sleeping state. The embodiments of the present disclosure are used for data stream transmission.